--- a/tests/test-bookmarks-pushpull.t	Tue Jun 20 17:25:57 2017 -0400
+++ b/tests/test-bookmarks-pushpull.t	Tue Jun 20 17:31:18 2017 -0400
@@ -809,7 +809,7 @@
   > ssh=ssh://user@dummy/issue4455-dest
   > http=http://localhost:$HGPORT/
   > [ui]
-  > ssh=python "$TESTDIR/dummyssh"
+  > ssh=$PYTHON "$TESTDIR/dummyssh"
   > EOF
   $ cat >> ../issue4455-dest/.hg/hgrc << EOF
   > [hooks]

--- a/tests/test-bundle2-exchange.t	Tue Jun 20 17:25:57 2017 -0400
+++ b/tests/test-bundle2-exchange.t	Tue Jun 20 17:31:18 2017 -0400
@@ -18,7 +18,7 @@
   > evolution=createmarkers,exchange
   > bundle2-output-capture=True
   > [ui]
-  > ssh=python "$TESTDIR/dummyssh"
+  > ssh=$PYTHON "$TESTDIR/dummyssh"
   > logtemplate={rev}:{node|short} {phase} {author} {bookmarks} {desc|firstline}
   > [web]
   > push_ssl = false
@@ -909,7 +909,7 @@
   $ cp $TESTTMP/hgrc.orig $HGRCPATH
   $ cat >> $HGRCPATH <<EOF
   > [ui]
-  > ssh=python "$TESTDIR/dummyssh"
+  > ssh=$PYTHON "$TESTDIR/dummyssh"
   > EOF
 
   $ cat >> $TESTTMP/locktester.py <<EOF

--- a/tests/test-bundle2-format.t	Tue Jun 20 17:25:57 2017 -0400
+++ b/tests/test-bundle2-format.t	Tue Jun 20 17:31:18 2017 -0400
@@ -229,7 +229,7 @@
   > [experimental]
   > evolution=createmarkers
   > [ui]
-  > ssh=python "$TESTDIR/dummyssh"
+  > ssh=$PYTHON "$TESTDIR/dummyssh"
   > logtemplate={rev}:{node|short} {phase} {author} {bookmarks} {desc|firstline}
   > [web]
   > push_ssl = false

--- a/tests/test-bundle2-remote-changegroup.t	Tue Jun 20 17:25:57 2017 -0400
+++ b/tests/test-bundle2-remote-changegroup.t	Tue Jun 20 17:31:18 2017 -0400
@@ -79,7 +79,7 @@
 
   $ cat >> $HGRCPATH << EOF
   > [ui]
-  > ssh=python "$TESTDIR/dummyssh"
+  > ssh=$PYTHON "$TESTDIR/dummyssh"
   > logtemplate={rev}:{node|short} {phase} {author} {bookmarks} {desc|firstline}
   > EOF
 

--- a/tests/test-clone.t	Tue Jun 20 17:25:57 2017 -0400
+++ b/tests/test-clone.t	Tue Jun 20 17:31:18 2017 -0400
@@ -1044,7 +1044,7 @@
   $ hg id -R remote -r 0
   abort: repository remote not found!
   [255]
-  $ hg --config share.pool=share -q clone -e "python \"$TESTDIR/dummyssh\"" a ssh://user@dummy/remote
+  $ hg --config share.pool=share -q clone -e "$PYTHON \"$TESTDIR/dummyssh\"" a ssh://user@dummy/remote
   $ hg -R remote id -r 0
   acb14030fe0a
 

--- a/tests/test-clonebundles.t	Tue Jun 20 17:25:57 2017 -0400
+++ b/tests/test-clonebundles.t	Tue Jun 20 17:31:18 2017 -0400
@@ -197,7 +197,7 @@
 
 Feature works over SSH
 
-  $ hg clone -U -e "python \"$TESTDIR/dummyssh\"" ssh://user@dummy/server ssh-full-clone
+  $ hg clone -U -e "$PYTHON \"$TESTDIR/dummyssh\"" ssh://user@dummy/server ssh-full-clone
   applying clone bundle from http://localhost:$HGPORT1/full.hg
   adding changesets
   adding manifests

--- a/tests/test-filebranch.t	Tue Jun 20 17:25:57 2017 -0400
+++ b/tests/test-filebranch.t	Tue Jun 20 17:31:18 2017 -0400
@@ -5,7 +5,7 @@
   > import sys, os
   > print "merging for", os.path.basename(sys.argv[1])
   > EOF
-  $ HGMERGE="python ../merge"; export HGMERGE
+  $ HGMERGE="$PYTHON ../merge"; export HGMERGE
 
 Creating base:
 

--- a/tests/test-http-branchmap.t	Tue Jun 20 17:25:57 2017 -0400
+++ b/tests/test-http-branchmap.t	Tue Jun 20 17:31:18 2017 -0400
@@ -87,7 +87,7 @@
   > EOF
   $ echo baz >> b/foo
   $ hg -R b ci -m baz
-  $ hg push -R b -e 'python oldhg' ssh://dummy/ --encoding latin1
+  $ hg push -R b -e '$PYTHON oldhg' ssh://dummy/ --encoding latin1
   pushing to ssh://dummy/
   searching for changes
   remote: adding changesets

--- a/tests/test-init.t	Tue Jun 20 17:25:57 2017 -0400
+++ b/tests/test-init.t	Tue Jun 20 17:31:18 2017 -0400
@@ -106,7 +106,7 @@
 
 init+push to remote2
 
-  $ hg init -e "python \"$TESTDIR/dummyssh\"" ssh://user@dummy/remote2
+  $ hg init -e "$PYTHON \"$TESTDIR/dummyssh\"" ssh://user@dummy/remote2
   $ hg incoming -R remote2 local
   comparing with local
   changeset:   0:08b9e9f63b32
@@ -116,7 +116,7 @@
   summary:     init
   
 
-  $ hg push -R local -e "python \"$TESTDIR/dummyssh\"" ssh://user@dummy/remote2
+  $ hg push -R local -e "$PYTHON \"$TESTDIR/dummyssh\"" ssh://user@dummy/remote2
   pushing to ssh://user@dummy/remote2
   searching for changes
   remote: adding changesets
@@ -126,7 +126,7 @@
 
 clone to remote1
 
-  $ hg clone -e "python \"$TESTDIR/dummyssh\"" local ssh://user@dummy/remote1
+  $ hg clone -e "$PYTHON \"$TESTDIR/dummyssh\"" local ssh://user@dummy/remote1
   searching for changes
   remote: adding changesets
   remote: adding manifests
@@ -134,7 +134,7 @@
   remote: added 1 changesets with 1 changes to 1 files
 
 The largefiles extension doesn't crash
-  $ hg clone -e "python \"$TESTDIR/dummyssh\"" local ssh://user@dummy/remotelf --config extensions.largefiles=
+  $ hg clone -e "$PYTHON \"$TESTDIR/dummyssh\"" local ssh://user@dummy/remotelf --config extensions.largefiles=
   The fsmonitor extension is incompatible with the largefiles extension and has been disabled. (fsmonitor !)
   The fsmonitor extension is incompatible with the largefiles extension and has been disabled. (fsmonitor !)
   searching for changes
@@ -145,14 +145,14 @@
 
 init to existing repo
 
-  $ hg init -e "python \"$TESTDIR/dummyssh\"" ssh://user@dummy/remote1
+  $ hg init -e "$PYTHON \"$TESTDIR/dummyssh\"" ssh://user@dummy/remote1
   abort: repository remote1 already exists!
   abort: could not create remote repo!
   [255]
 
 clone to existing repo
 
-  $ hg clone -e "python \"$TESTDIR/dummyssh\"" local ssh://user@dummy/remote1
+  $ hg clone -e "$PYTHON \"$TESTDIR/dummyssh\"" local ssh://user@dummy/remote1
   abort: repository remote1 already exists!
   abort: could not create remote repo!
   [255]
@@ -251,7 +251,7 @@
   $ hg -R local bookmark test
   $ hg -R local bookmarks
    * test                      0:08b9e9f63b32
-  $ hg clone -e "python \"$TESTDIR/dummyssh\"" local ssh://user@dummy/remote-bookmarks
+  $ hg clone -e "$PYTHON \"$TESTDIR/dummyssh\"" local ssh://user@dummy/remote-bookmarks
   searching for changes
   remote: adding changesets
   remote: adding manifests

--- a/tests/test-largefiles-wireproto.t	Tue Jun 20 17:25:57 2017 -0400
+++ b/tests/test-largefiles-wireproto.t	Tue Jun 20 17:31:18 2017 -0400
@@ -112,7 +112,7 @@
 #endif
 
 vanilla clients locked out from largefiles ssh repos
-  $ hg --config extensions.largefiles=! clone -e "python \"$TESTDIR/dummyssh\"" ssh://user@dummy/r4 r5
+  $ hg --config extensions.largefiles=! clone -e "$PYTHON \"$TESTDIR/dummyssh\"" ssh://user@dummy/r4 r5
   remote: 
   remote: This repository uses the largefiles extension.
   remote: 

--- a/tests/test-merge1.t	Tue Jun 20 17:25:57 2017 -0400
+++ b/tests/test-merge1.t	Tue Jun 20 17:31:18 2017 -0400
@@ -10,7 +10,7 @@
   > 
   > print "merging for", os.path.basename(sys.argv[1])
   > EOF
-  $ HGMERGE="python ../merge"; export HGMERGE
+  $ HGMERGE="$PYTHON ../merge"; export HGMERGE
 
   $ hg init t
   $ cd t

--- a/tests/test-merge6.t	Tue Jun 20 17:25:57 2017 -0400
+++ b/tests/test-merge6.t	Tue Jun 20 17:31:18 2017 -0400
@@ -2,7 +2,7 @@
   > import sys, os
   > print "merging for", os.path.basename(sys.argv[1])
   > EOF
-  $ HGMERGE="python ../merge"; export HGMERGE
+  $ HGMERGE="$PYTHON ../merge"; export HGMERGE
 
   $ hg init A1
   $ cd A1

--- a/tests/test-rename-merge2.t	Tue Jun 20 17:25:57 2017 -0400
+++ b/tests/test-rename-merge2.t	Tue Jun 20 17:31:18 2017 -0400
@@ -47,7 +47,7 @@
   >     echo "--------------"
   >     echo "test L:$1 R:$2 W:$3 - $4"
   >     echo "--------------"
-  >     hg merge -y --debug --traceback --tool="python ../merge"
+  >     hg merge -y --debug --traceback --tool="$PYTHON ../merge"
   > 
   >     echo "--------------"
   >     hg status -camC -X rev
@@ -90,18 +90,18 @@
    preserving rev for resolve of rev
   starting 4 threads for background file closing (?)
    b: remote copied from a -> m (premerge)
-  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
+  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
   merging a and b to b
   my b@e300d1c794ec+ other b@4ce40f5aca24 ancestor a@924404dff337
    premerge successful
    rev: versions differ -> m (premerge)
-  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
+  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
   merging rev
   my rev@e300d1c794ec+ other rev@4ce40f5aca24 ancestor rev@924404dff337
    rev: versions differ -> m (merge)
-  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
+  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
   my rev@e300d1c794ec+ other rev@4ce40f5aca24 ancestor rev@924404dff337
-  launching merge tool: python ../merge *$TESTTMP/t/t/rev* * * (glob)
+  launching merge tool: * ../merge *$TESTTMP/t/t/rev* * * (glob)
   merge tool returned: 0
   0 files updated, 2 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
@@ -130,18 +130,18 @@
    a: remote is newer -> g
   getting a
    b: local copied/moved from a -> m (premerge)
-  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
+  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
   merging b and a to b
   my b@86a2aa42fc76+ other a@f4db7e329e71 ancestor a@924404dff337
    premerge successful
    rev: versions differ -> m (premerge)
-  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
+  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
   merging rev
   my rev@86a2aa42fc76+ other rev@f4db7e329e71 ancestor rev@924404dff337
    rev: versions differ -> m (merge)
-  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
+  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
   my rev@86a2aa42fc76+ other rev@f4db7e329e71 ancestor rev@924404dff337
-  launching merge tool: python ../merge *$TESTTMP/t/t/rev* * * (glob)
+  launching merge tool: * ../merge *$TESTTMP/t/t/rev* * * (glob)
   merge tool returned: 0
   1 files updated, 2 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
@@ -170,18 +170,18 @@
   removing a
   starting 4 threads for background file closing (?)
    b: remote moved from a -> m (premerge)
-  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
+  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
   merging a and b to b
   my b@e300d1c794ec+ other b@bdb19105162a ancestor a@924404dff337
    premerge successful
    rev: versions differ -> m (premerge)
-  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
+  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
   merging rev
   my rev@e300d1c794ec+ other rev@bdb19105162a ancestor rev@924404dff337
    rev: versions differ -> m (merge)
-  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
+  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
   my rev@e300d1c794ec+ other rev@bdb19105162a ancestor rev@924404dff337
-  launching merge tool: python ../merge *$TESTTMP/t/t/rev* * * (glob)
+  launching merge tool: * ../merge *$TESTTMP/t/t/rev* * * (glob)
   merge tool returned: 0
   0 files updated, 2 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
@@ -208,18 +208,18 @@
    preserving rev for resolve of rev
   starting 4 threads for background file closing (?)
    b: local copied/moved from a -> m (premerge)
-  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
+  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
   merging b and a to b
   my b@02963e448370+ other a@f4db7e329e71 ancestor a@924404dff337
    premerge successful
    rev: versions differ -> m (premerge)
-  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
+  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
   merging rev
   my rev@02963e448370+ other rev@f4db7e329e71 ancestor rev@924404dff337
    rev: versions differ -> m (merge)
-  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
+  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
   my rev@02963e448370+ other rev@f4db7e329e71 ancestor rev@924404dff337
-  launching merge tool: python ../merge *$TESTTMP/t/t/rev* * * (glob)
+  launching merge tool: * ../merge *$TESTTMP/t/t/rev* * * (glob)
   merge tool returned: 0
   0 files updated, 2 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
@@ -246,13 +246,13 @@
    b: remote created -> g
   getting b
    rev: versions differ -> m (premerge)
-  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
+  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
   merging rev
   my rev@94b33a1b7f2d+ other rev@4ce40f5aca24 ancestor rev@924404dff337
    rev: versions differ -> m (merge)
-  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
+  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
   my rev@94b33a1b7f2d+ other rev@4ce40f5aca24 ancestor rev@924404dff337
-  launching merge tool: python ../merge *$TESTTMP/t/t/rev* * * (glob)
+  launching merge tool: * ../merge *$TESTTMP/t/t/rev* * * (glob)
   merge tool returned: 0
   1 files updated, 1 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
@@ -278,13 +278,13 @@
    preserving rev for resolve of rev
   starting 4 threads for background file closing (?)
    rev: versions differ -> m (premerge)
-  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
+  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
   merging rev
   my rev@86a2aa42fc76+ other rev@97c705ade336 ancestor rev@924404dff337
    rev: versions differ -> m (merge)
-  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
+  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
   my rev@86a2aa42fc76+ other rev@97c705ade336 ancestor rev@924404dff337
-  launching merge tool: python ../merge *$TESTTMP/t/t/rev* * * (glob)
+  launching merge tool: * ../merge *$TESTTMP/t/t/rev* * * (glob)
   merge tool returned: 0
   0 files updated, 1 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
@@ -313,13 +313,13 @@
    b: remote created -> g
   getting b
    rev: versions differ -> m (premerge)
-  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
+  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
   merging rev
   my rev@94b33a1b7f2d+ other rev@bdb19105162a ancestor rev@924404dff337
    rev: versions differ -> m (merge)
-  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
+  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
   my rev@94b33a1b7f2d+ other rev@bdb19105162a ancestor rev@924404dff337
-  launching merge tool: python ../merge *$TESTTMP/t/t/rev* * * (glob)
+  launching merge tool: * ../merge *$TESTTMP/t/t/rev* * * (glob)
   merge tool returned: 0
   1 files updated, 1 files merged, 1 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
@@ -344,13 +344,13 @@
    preserving rev for resolve of rev
   starting 4 threads for background file closing (?)
    rev: versions differ -> m (premerge)
-  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
+  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
   merging rev
   my rev@02963e448370+ other rev@97c705ade336 ancestor rev@924404dff337
    rev: versions differ -> m (merge)
-  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
+  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
   my rev@02963e448370+ other rev@97c705ade336 ancestor rev@924404dff337
-  launching merge tool: python ../merge *$TESTTMP/t/t/rev* * * (glob)
+  launching merge tool: * ../merge *$TESTTMP/t/t/rev* * * (glob)
   merge tool returned: 0
   0 files updated, 1 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
@@ -373,22 +373,22 @@
    preserving rev for resolve of rev
   starting 4 threads for background file closing (?)
    b: both renamed from a -> m (premerge)
-  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
+  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
   merging b
   my b@62e7bf090eba+ other b@49b6d8032493 ancestor a@924404dff337
    rev: versions differ -> m (premerge)
-  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
+  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
   merging rev
   my rev@62e7bf090eba+ other rev@49b6d8032493 ancestor rev@924404dff337
    b: both renamed from a -> m (merge)
-  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
+  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
   my b@62e7bf090eba+ other b@49b6d8032493 ancestor a@924404dff337
-  launching merge tool: python ../merge *$TESTTMP/t/t/b* * * (glob)
+  launching merge tool: * ../merge *$TESTTMP/t/t/b* * * (glob)
   merge tool returned: 0
    rev: versions differ -> m (merge)
-  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
+  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
   my rev@62e7bf090eba+ other rev@49b6d8032493 ancestor rev@924404dff337
-  launching merge tool: python ../merge *$TESTTMP/t/t/rev* * * (glob)
+  launching merge tool: * ../merge *$TESTTMP/t/t/rev* * * (glob)
   merge tool returned: 0
   0 files updated, 2 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
@@ -423,13 +423,13 @@
    c: remote created -> g
   getting c
    rev: versions differ -> m (premerge)
-  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
+  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
   merging rev
   my rev@02963e448370+ other rev@fe905ef2c33e ancestor rev@924404dff337
    rev: versions differ -> m (merge)
-  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
+  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
   my rev@02963e448370+ other rev@fe905ef2c33e ancestor rev@924404dff337
-  launching merge tool: python ../merge *$TESTTMP/t/t/rev* * * (glob)
+  launching merge tool: * ../merge *$TESTTMP/t/t/rev* * * (glob)
   merge tool returned: 0
   1 files updated, 1 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
@@ -453,22 +453,22 @@
    preserving rev for resolve of rev
   starting 4 threads for background file closing (?)
    b: both created -> m (premerge)
-  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
+  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
   merging b
   my b@86a2aa42fc76+ other b@af30c7647fc7 ancestor b@000000000000
    rev: versions differ -> m (premerge)
-  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
+  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
   merging rev
   my rev@86a2aa42fc76+ other rev@af30c7647fc7 ancestor rev@924404dff337
    b: both created -> m (merge)
-  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
+  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
   my b@86a2aa42fc76+ other b@af30c7647fc7 ancestor b@000000000000
-  launching merge tool: python ../merge *$TESTTMP/t/t/b* * * (glob)
+  launching merge tool: * ../merge *$TESTTMP/t/t/b* * * (glob)
   merge tool returned: 0
    rev: versions differ -> m (merge)
-  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
+  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
   my rev@86a2aa42fc76+ other rev@af30c7647fc7 ancestor rev@924404dff337
-  launching merge tool: python ../merge *$TESTTMP/t/t/rev* * * (glob)
+  launching merge tool: * ../merge *$TESTTMP/t/t/rev* * * (glob)
   merge tool returned: 0
   0 files updated, 2 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
@@ -494,22 +494,22 @@
   removing a
   starting 4 threads for background file closing (?)
    b: both created -> m (premerge)
-  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
+  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
   merging b
   my b@59318016310c+ other b@bdb19105162a ancestor b@000000000000
    rev: versions differ -> m (premerge)
-  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
+  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
   merging rev
   my rev@59318016310c+ other rev@bdb19105162a ancestor rev@924404dff337
    b: both created -> m (merge)
-  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
+  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
   my b@59318016310c+ other b@bdb19105162a ancestor b@000000000000
-  launching merge tool: python ../merge *$TESTTMP/t/t/b* * * (glob)
+  launching merge tool: * ../merge *$TESTTMP/t/t/b* * * (glob)
   merge tool returned: 0
    rev: versions differ -> m (merge)
-  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
+  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
   my rev@59318016310c+ other rev@bdb19105162a ancestor rev@924404dff337
-  launching merge tool: python ../merge *$TESTTMP/t/t/rev* * * (glob)
+  launching merge tool: * ../merge *$TESTTMP/t/t/rev* * * (glob)
   merge tool returned: 0
   0 files updated, 2 files merged, 1 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
@@ -533,22 +533,22 @@
    a: remote is newer -> g
   getting a
    b: both created -> m (premerge)
-  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
+  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
   merging b
   my b@86a2aa42fc76+ other b@8dbce441892a ancestor b@000000000000
    rev: versions differ -> m (premerge)
-  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
+  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
   merging rev
   my rev@86a2aa42fc76+ other rev@8dbce441892a ancestor rev@924404dff337
    b: both created -> m (merge)
-  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
+  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
   my b@86a2aa42fc76+ other b@8dbce441892a ancestor b@000000000000
-  launching merge tool: python ../merge *$TESTTMP/t/t/b* * * (glob)
+  launching merge tool: * ../merge *$TESTTMP/t/t/b* * * (glob)
   merge tool returned: 0
    rev: versions differ -> m (merge)
-  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
+  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
   my rev@86a2aa42fc76+ other rev@8dbce441892a ancestor rev@924404dff337
-  launching merge tool: python ../merge *$TESTTMP/t/t/rev* * * (glob)
+  launching merge tool: * ../merge *$TESTTMP/t/t/rev* * * (glob)
   merge tool returned: 0
   1 files updated, 2 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
@@ -574,22 +574,22 @@
   removing a
   starting 4 threads for background file closing (?)
    b: both created -> m (premerge)
-  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
+  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
   merging b
   my b@59318016310c+ other b@bdb19105162a ancestor b@000000000000
    rev: versions differ -> m (premerge)
-  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
+  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
   merging rev
   my rev@59318016310c+ other rev@bdb19105162a ancestor rev@924404dff337
    b: both created -> m (merge)
-  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
+  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
   my b@59318016310c+ other b@bdb19105162a ancestor b@000000000000
-  launching merge tool: python ../merge *$TESTTMP/t/t/b* * * (glob)
+  launching merge tool: * ../merge *$TESTTMP/t/t/b* * * (glob)
   merge tool returned: 0
    rev: versions differ -> m (merge)
-  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
+  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
   my rev@59318016310c+ other rev@bdb19105162a ancestor rev@924404dff337
-  launching merge tool: python ../merge *$TESTTMP/t/t/rev* * * (glob)
+  launching merge tool: * ../merge *$TESTTMP/t/t/rev* * * (glob)
   merge tool returned: 0
   0 files updated, 2 files merged, 1 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
@@ -613,22 +613,22 @@
    a: remote is newer -> g
   getting a
    b: both created -> m (premerge)
-  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
+  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
   merging b
   my b@86a2aa42fc76+ other b@8dbce441892a ancestor b@000000000000
    rev: versions differ -> m (premerge)
-  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
+  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
   merging rev
   my rev@86a2aa42fc76+ other rev@8dbce441892a ancestor rev@924404dff337
    b: both created -> m (merge)
-  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
+  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
   my b@86a2aa42fc76+ other b@8dbce441892a ancestor b@000000000000
-  launching merge tool: python ../merge *$TESTTMP/t/t/b* * * (glob)
+  launching merge tool: * ../merge *$TESTTMP/t/t/b* * * (glob)
   merge tool returned: 0
    rev: versions differ -> m (merge)
-  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
+  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
   my rev@86a2aa42fc76+ other rev@8dbce441892a ancestor rev@924404dff337
-  launching merge tool: python ../merge *$TESTTMP/t/t/rev* * * (glob)
+  launching merge tool: * ../merge *$TESTTMP/t/t/rev* * * (glob)
   merge tool returned: 0
   1 files updated, 2 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
@@ -652,22 +652,22 @@
    preserving rev for resolve of rev
   starting 4 threads for background file closing (?)
    b: both created -> m (premerge)
-  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
+  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
   merging b
   my b@0b76e65c8289+ other b@4ce40f5aca24 ancestor b@000000000000
    rev: versions differ -> m (premerge)
-  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
+  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
   merging rev
   my rev@0b76e65c8289+ other rev@4ce40f5aca24 ancestor rev@924404dff337
    b: both created -> m (merge)
-  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
+  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
   my b@0b76e65c8289+ other b@4ce40f5aca24 ancestor b@000000000000
-  launching merge tool: python ../merge *$TESTTMP/t/t/b* * * (glob)
+  launching merge tool: * ../merge *$TESTTMP/t/t/b* * * (glob)
   merge tool returned: 0
    rev: versions differ -> m (merge)
-  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
+  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
   my rev@0b76e65c8289+ other rev@4ce40f5aca24 ancestor rev@924404dff337
-  launching merge tool: python ../merge *$TESTTMP/t/t/rev* * * (glob)
+  launching merge tool: * ../merge *$TESTTMP/t/t/rev* * * (glob)
   merge tool returned: 0
   0 files updated, 2 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
@@ -695,22 +695,22 @@
   other [merge rev] changed a which local [working copy] deleted
   use (c)hanged version, leave (d)eleted, or leave (u)nresolved? u
    b: both created -> m (premerge)
-  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
+  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
   merging b
   my b@02963e448370+ other b@8dbce441892a ancestor b@000000000000
    rev: versions differ -> m (premerge)
-  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
+  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
   merging rev
   my rev@02963e448370+ other rev@8dbce441892a ancestor rev@924404dff337
    b: both created -> m (merge)
-  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
+  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
   my b@02963e448370+ other b@8dbce441892a ancestor b@000000000000
-  launching merge tool: python ../merge *$TESTTMP/t/t/b* * * (glob)
+  launching merge tool: * ../merge *$TESTTMP/t/t/b* * * (glob)
   merge tool returned: 0
    rev: versions differ -> m (merge)
-  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
+  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
   my rev@02963e448370+ other rev@8dbce441892a ancestor rev@924404dff337
-  launching merge tool: python ../merge *$TESTTMP/t/t/rev* * * (glob)
+  launching merge tool: * ../merge *$TESTTMP/t/t/rev* * * (glob)
   merge tool returned: 0
   0 files updated, 2 files merged, 0 files removed, 1 files unresolved
   use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
@@ -740,22 +740,22 @@
   local [working copy] changed a which other [merge rev] deleted
   use (c)hanged version, (d)elete, or leave (u)nresolved? u
    b: both created -> m (premerge)
-  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
+  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
   merging b
   my b@0b76e65c8289+ other b@bdb19105162a ancestor b@000000000000
    rev: versions differ -> m (premerge)
-  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
+  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
   merging rev
   my rev@0b76e65c8289+ other rev@bdb19105162a ancestor rev@924404dff337
    b: both created -> m (merge)
-  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
+  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
   my b@0b76e65c8289+ other b@bdb19105162a ancestor b@000000000000
-  launching merge tool: python ../merge *$TESTTMP/t/t/b* * * (glob)
+  launching merge tool: * ../merge *$TESTTMP/t/t/b* * * (glob)
   merge tool returned: 0
    rev: versions differ -> m (merge)
-  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
+  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
   my rev@0b76e65c8289+ other rev@bdb19105162a ancestor rev@924404dff337
-  launching merge tool: python ../merge *$TESTTMP/t/t/rev* * * (glob)
+  launching merge tool: * ../merge *$TESTTMP/t/t/rev* * * (glob)
   merge tool returned: 0
   0 files updated, 2 files merged, 0 files removed, 1 files unresolved
   use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
@@ -784,22 +784,22 @@
   removing a
   starting 4 threads for background file closing (?)
    b: remote moved from a -> m (premerge)
-  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
+  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
   merging a and b to b
   my b@e300d1c794ec+ other b@49b6d8032493 ancestor a@924404dff337
    rev: versions differ -> m (premerge)
-  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
+  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
   merging rev
   my rev@e300d1c794ec+ other rev@49b6d8032493 ancestor rev@924404dff337
    b: remote moved from a -> m (merge)
-  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
+  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
   my b@e300d1c794ec+ other b@49b6d8032493 ancestor a@924404dff337
-  launching merge tool: python ../merge *$TESTTMP/t/t/b* * * (glob)
+  launching merge tool: * ../merge *$TESTTMP/t/t/b* * * (glob)
   merge tool returned: 0
    rev: versions differ -> m (merge)
-  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
+  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
   my rev@e300d1c794ec+ other rev@49b6d8032493 ancestor rev@924404dff337
-  launching merge tool: python ../merge *$TESTTMP/t/t/rev* * * (glob)
+  launching merge tool: * ../merge *$TESTTMP/t/t/rev* * * (glob)
   merge tool returned: 0
   0 files updated, 2 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
@@ -826,22 +826,22 @@
    preserving rev for resolve of rev
   starting 4 threads for background file closing (?)
    b: local copied/moved from a -> m (premerge)
-  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
+  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
   merging b and a to b
   my b@62e7bf090eba+ other a@f4db7e329e71 ancestor a@924404dff337
    rev: versions differ -> m (premerge)
-  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
+  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
   merging rev
   my rev@62e7bf090eba+ other rev@f4db7e329e71 ancestor rev@924404dff337
    b: local copied/moved from a -> m (merge)
-  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
+  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
   my b@62e7bf090eba+ other a@f4db7e329e71 ancestor a@924404dff337
-  launching merge tool: python ../merge *$TESTTMP/t/t/b* * * (glob)
+  launching merge tool: * ../merge *$TESTTMP/t/t/b* * * (glob)
   merge tool returned: 0
    rev: versions differ -> m (merge)
-  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
+  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
   my rev@62e7bf090eba+ other rev@f4db7e329e71 ancestor rev@924404dff337
-  launching merge tool: python ../merge *$TESTTMP/t/t/rev* * * (glob)
+  launching merge tool: * ../merge *$TESTTMP/t/t/rev* * * (glob)
   merge tool returned: 0
   0 files updated, 2 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
@@ -874,18 +874,18 @@
    c: remote created -> g
   getting c
    b: local copied/moved from a -> m (premerge)
-  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
+  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
   merging b and a to b
   my b@02963e448370+ other a@2b958612230f ancestor a@924404dff337
    premerge successful
    rev: versions differ -> m (premerge)
-  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
+  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
   merging rev
   my rev@02963e448370+ other rev@2b958612230f ancestor rev@924404dff337
    rev: versions differ -> m (merge)
-  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
+  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
   my rev@02963e448370+ other rev@2b958612230f ancestor rev@924404dff337
-  launching merge tool: python ../merge *$TESTTMP/t/t/rev* * * (glob)
+  launching merge tool: * ../merge *$TESTTMP/t/t/rev* * * (glob)
   merge tool returned: 0
   1 files updated, 2 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)

--- a/tests/test-revset.t	Tue Jun 20 17:25:57 2017 -0400
+++ b/tests/test-revset.t	Tue Jun 20 17:31:18 2017 -0400
@@ -3065,14 +3065,14 @@
 test that chained `or` operations never eat up stack (issue4624)
 (uses `0:1` instead of `0` to avoid future optimization of trivial revisions)
 
-  $ hg log -T '{rev}\n' -r `python -c "print '+'.join(['0:1'] * 500)"`
+  $ hg log -T '{rev}\n' -r `$PYTHON -c "print '+'.join(['0:1'] * 500)"`
   0
   1
 
 test that repeated `-r` options never eat up stack (issue4565)
 (uses `-r 0::1` to avoid possible optimization at old-style parser)
 
-  $ hg log -T '{rev}\n' `python -c "for i in xrange(500): print '-r 0::1 ',"`
+  $ hg log -T '{rev}\n' `$PYTHON -c "for i in xrange(500): print '-r 0::1 ',"`
   0
   1
 

--- a/tests/test-ssh-bundle1.t	Tue Jun 20 17:25:57 2017 -0400
+++ b/tests/test-ssh-bundle1.t	Tue Jun 20 17:31:18 2017 -0400
@@ -44,21 +44,21 @@
 
 repo not found error
 
-  $ hg clone -e "python \"$TESTDIR/dummyssh\"" ssh://user@dummy/nonexistent local
+  $ hg clone -e "$PYTHON \"$TESTDIR/dummyssh\"" ssh://user@dummy/nonexistent local
   remote: abort: repository nonexistent not found!
   abort: no suitable response from remote hg!
   [255]
 
 non-existent absolute path
 
-  $ hg clone -e "python \"$TESTDIR/dummyssh\"" ssh://user@dummy//`pwd`/nonexistent local
+  $ hg clone -e "$PYTHON \"$TESTDIR/dummyssh\"" ssh://user@dummy//`pwd`/nonexistent local
   remote: abort: repository /$TESTTMP/nonexistent not found!
   abort: no suitable response from remote hg!
   [255]
 
 clone remote via stream
 
-  $ hg clone -e "python \"$TESTDIR/dummyssh\"" --uncompressed ssh://user@dummy/remote local-stream
+  $ hg clone -e "$PYTHON \"$TESTDIR/dummyssh\"" --uncompressed ssh://user@dummy/remote local-stream
   streaming all changes
   4 files to transfer, 602 bytes of data
   transferred 602 bytes in * seconds (*) (glob)
@@ -80,7 +80,7 @@
 clone bookmarks via stream
 
   $ hg -R local-stream book mybook
-  $ hg clone -e "python \"$TESTDIR/dummyssh\"" --uncompressed ssh://user@dummy/local-stream stream2
+  $ hg clone -e "$PYTHON \"$TESTDIR/dummyssh\"" --uncompressed ssh://user@dummy/local-stream stream2
   streaming all changes
   4 files to transfer, 602 bytes of data
   transferred 602 bytes in * seconds (*) (glob)
@@ -96,7 +96,7 @@
 
 clone remote via pull
 
-  $ hg clone -e "python \"$TESTDIR/dummyssh\"" ssh://user@dummy/remote local
+  $ hg clone -e "$PYTHON \"$TESTDIR/dummyssh\"" ssh://user@dummy/remote local
   requesting all changes
   adding changesets
   adding manifests
@@ -123,14 +123,14 @@
 
   $ hg paths
   default = ssh://user@dummy/remote
-  $ hg pull -e "python \"$TESTDIR/dummyssh\""
+  $ hg pull -e "$PYTHON \"$TESTDIR/dummyssh\""
   pulling from ssh://user@dummy/remote
   searching for changes
   no changes found
 
 pull from wrong ssh URL
 
-  $ hg pull -e "python \"$TESTDIR/dummyssh\"" ssh://user@dummy/doesnotexist
+  $ hg pull -e "$PYTHON \"$TESTDIR/dummyssh\"" ssh://user@dummy/doesnotexist
   pulling from ssh://user@dummy/doesnotexist
   remote: abort: repository doesnotexist not found!
   abort: no suitable response from remote hg!
@@ -162,7 +162,7 @@
 
 find incoming on the remote side
 
-  $ hg incoming -R ../remote -e "python \"$TESTDIR/dummyssh\"" ssh://user@dummy/local
+  $ hg incoming -R ../remote -e "$PYTHON \"$TESTDIR/dummyssh\"" ssh://user@dummy/local
   comparing with ssh://user@dummy/local
   searching for changes
   changeset:   3:a28a9d1a809c
@@ -175,7 +175,7 @@
 
 find incoming on the remote side (using absolute path)
 
-  $ hg incoming -R ../remote -e "python \"$TESTDIR/dummyssh\"" "ssh://user@dummy/`pwd`"
+  $ hg incoming -R ../remote -e "$PYTHON \"$TESTDIR/dummyssh\"" "ssh://user@dummy/`pwd`"
   comparing with ssh://user@dummy/$TESTTMP/local
   searching for changes
   changeset:   3:a28a9d1a809c
@@ -222,7 +222,7 @@
 test pushkeys and bookmarks
 
   $ cd ../local
-  $ hg debugpushkey --config ui.ssh="python \"$TESTDIR/dummyssh\"" ssh://user@dummy/remote namespaces
+  $ hg debugpushkey --config ui.ssh="$PYTHON \"$TESTDIR/dummyssh\"" ssh://user@dummy/remote namespaces
   bookmarks	
   namespaces	
   phases	
@@ -237,7 +237,7 @@
   no changes found
   exporting bookmark foo
   [1]
-  $ hg debugpushkey --config ui.ssh="python \"$TESTDIR/dummyssh\"" ssh://user@dummy/remote bookmarks
+  $ hg debugpushkey --config ui.ssh="$PYTHON \"$TESTDIR/dummyssh\"" ssh://user@dummy/remote bookmarks
   foo	1160648e36cec0054048a7edc4110c6f84fde594
   $ hg book -f foo
   $ hg push --traceback
@@ -307,7 +307,7 @@
   $ hg -R ../remote bookmark test
   $ hg -R ../remote bookmarks
    * test                      4:6c0482d977a3
-  $ hg clone -e "python \"$TESTDIR/dummyssh\"" ssh://user@dummy/remote local-bookmarks
+  $ hg clone -e "$PYTHON \"$TESTDIR/dummyssh\"" ssh://user@dummy/remote local-bookmarks
   requesting all changes
   adding changesets
   adding manifests
@@ -334,21 +334,21 @@
 
 Test remote paths with spaces (issue2983):
 
-  $ hg init --ssh "python \"$TESTDIR/dummyssh\"" "ssh://user@dummy/a repo"
+  $ hg init --ssh "$PYTHON \"$TESTDIR/dummyssh\"" "ssh://user@dummy/a repo"
   $ touch "$TESTTMP/a repo/test"
   $ hg -R 'a repo' commit -A -m "test"
   adding test
   $ hg -R 'a repo' tag tag
-  $ hg id --ssh "python \"$TESTDIR/dummyssh\"" "ssh://user@dummy/a repo"
+  $ hg id --ssh "$PYTHON \"$TESTDIR/dummyssh\"" "ssh://user@dummy/a repo"
   73649e48688a
 
-  $ hg id --ssh "python \"$TESTDIR/dummyssh\"" "ssh://user@dummy/a repo#noNoNO"
+  $ hg id --ssh "$PYTHON \"$TESTDIR/dummyssh\"" "ssh://user@dummy/a repo#noNoNO"
   abort: unknown revision 'noNoNO'!
   [255]
 
 Test (non-)escaping of remote paths with spaces when cloning (issue3145):
 
-  $ hg clone --ssh "python \"$TESTDIR/dummyssh\"" "ssh://user@dummy/a repo"
+  $ hg clone --ssh "$PYTHON \"$TESTDIR/dummyssh\"" "ssh://user@dummy/a repo"
   destination directory: a repo
   abort: destination 'a repo' is not empty
   [255]
@@ -526,11 +526,11 @@
 
   $ echo "pretxnchangegroup.fail = python:$TESTTMP/failhook:hook" >> remote/.hg/hgrc
 
-  $ hg -q --config ui.ssh="python $TESTDIR/dummyssh" clone ssh://user@dummy/remote hookout
+  $ hg -q --config ui.ssh="$PYTHON $TESTDIR/dummyssh" clone ssh://user@dummy/remote hookout
   $ cd hookout
   $ touch hookfailure
   $ hg -q commit -A -m 'remote hook failure'
-  $ hg --config ui.ssh="python $TESTDIR/dummyssh" push
+  $ hg --config ui.ssh="$PYTHON $TESTDIR/dummyssh" push
   pushing to ssh://user@dummy/remote
   searching for changes
   remote: adding changesets
@@ -551,7 +551,7 @@
   > [extensions]
   > crash = ${TESTDIR}/crashgetbundler.py
   > EOF
-  $ hg --config ui.ssh="python $TESTDIR/dummyssh" pull
+  $ hg --config ui.ssh="$PYTHON $TESTDIR/dummyssh" pull
   pulling from ssh://user@dummy/remote
   searching for changes
   adding changesets

--- a/tests/test-ssh-clone-r.t	Tue Jun 20 17:25:57 2017 -0400
+++ b/tests/test-ssh-clone-r.t	Tue Jun 20 17:31:18 2017 -0400
@@ -17,7 +17,7 @@
 clone remote via stream
 
   $ for i in 0 1 2 3 4 5 6 7 8; do
-  >    hg clone -e "python \"$TESTDIR/dummyssh\"" --uncompressed -r "$i" ssh://user@dummy/remote test-"$i"
+  >    hg clone -e "$PYTHON \"$TESTDIR/dummyssh\"" --uncompressed -r "$i" ssh://user@dummy/remote test-"$i"
   >    if cd test-"$i"; then
   >       hg verify
   >       cd ..
@@ -139,7 +139,7 @@
   4 files, 9 changesets, 7 total revisions
   $ cd ..
   $ cd test-1
-  $ hg pull -e "python \"$TESTDIR/dummyssh\"" -r 4 ssh://user@dummy/remote
+  $ hg pull -e "$PYTHON \"$TESTDIR/dummyssh\"" -r 4 ssh://user@dummy/remote
   pulling from ssh://user@dummy/remote
   searching for changes
   adding changesets
@@ -153,7 +153,7 @@
   crosschecking files in changesets and manifests
   checking files
   1 files, 3 changesets, 2 total revisions
-  $ hg pull -e "python \"$TESTDIR/dummyssh\"" ssh://user@dummy/remote
+  $ hg pull -e "$PYTHON \"$TESTDIR/dummyssh\"" ssh://user@dummy/remote
   pulling from ssh://user@dummy/remote
   searching for changes
   adding changesets
@@ -163,7 +163,7 @@
   (run 'hg update' to get a working copy)
   $ cd ..
   $ cd test-2
-  $ hg pull -e "python \"$TESTDIR/dummyssh\"" -r 5 ssh://user@dummy/remote
+  $ hg pull -e "$PYTHON \"$TESTDIR/dummyssh\"" -r 5 ssh://user@dummy/remote
   pulling from ssh://user@dummy/remote
   searching for changes
   adding changesets
@@ -177,7 +177,7 @@
   crosschecking files in changesets and manifests
   checking files
   1 files, 5 changesets, 3 total revisions
-  $ hg pull -e "python \"$TESTDIR/dummyssh\"" ssh://user@dummy/remote
+  $ hg pull -e "$PYTHON \"$TESTDIR/dummyssh\"" ssh://user@dummy/remote
   pulling from ssh://user@dummy/remote
   searching for changes
   adding changesets

--- a/tests/test-ssh.t	Tue Jun 20 17:25:57 2017 -0400
+++ b/tests/test-ssh.t	Tue Jun 20 17:31:18 2017 -0400
@@ -38,21 +38,21 @@
 
 repo not found error
 
-  $ hg clone -e "python \"$TESTDIR/dummyssh\"" ssh://user@dummy/nonexistent local
+  $ hg clone -e "$PYTHON \"$TESTDIR/dummyssh\"" ssh://user@dummy/nonexistent local
   remote: abort: repository nonexistent not found!
   abort: no suitable response from remote hg!
   [255]
 
 non-existent absolute path
 
-  $ hg clone -e "python \"$TESTDIR/dummyssh\"" ssh://user@dummy/`pwd`/nonexistent local
+  $ hg clone -e "$PYTHON \"$TESTDIR/dummyssh\"" ssh://user@dummy/`pwd`/nonexistent local
   remote: abort: repository $TESTTMP/nonexistent not found!
   abort: no suitable response from remote hg!
   [255]
 
 clone remote via stream
 
-  $ hg clone -e "python \"$TESTDIR/dummyssh\"" --uncompressed ssh://user@dummy/remote local-stream
+  $ hg clone -e "$PYTHON \"$TESTDIR/dummyssh\"" --uncompressed ssh://user@dummy/remote local-stream
   streaming all changes
   4 files to transfer, 602 bytes of data
   transferred 602 bytes in * seconds (*) (glob)
@@ -74,7 +74,7 @@
 clone bookmarks via stream
 
   $ hg -R local-stream book mybook
-  $ hg clone -e "python \"$TESTDIR/dummyssh\"" --uncompressed ssh://user@dummy/local-stream stream2
+  $ hg clone -e "$PYTHON \"$TESTDIR/dummyssh\"" --uncompressed ssh://user@dummy/local-stream stream2
   streaming all changes
   4 files to transfer, 602 bytes of data
   transferred 602 bytes in * seconds (*) (glob)
@@ -90,7 +90,7 @@
 
 clone remote via pull
 
-  $ hg clone -e "python \"$TESTDIR/dummyssh\"" ssh://user@dummy/remote local
+  $ hg clone -e "$PYTHON \"$TESTDIR/dummyssh\"" ssh://user@dummy/remote local
   requesting all changes
   adding changesets
   adding manifests
@@ -117,14 +117,14 @@
 
   $ hg paths
   default = ssh://user@dummy/remote
-  $ hg pull -e "python \"$TESTDIR/dummyssh\""
+  $ hg pull -e "$PYTHON \"$TESTDIR/dummyssh\""
   pulling from ssh://user@dummy/remote
   searching for changes
   no changes found
 
 pull from wrong ssh URL
 
-  $ hg pull -e "python \"$TESTDIR/dummyssh\"" ssh://user@dummy/doesnotexist
+  $ hg pull -e "$PYTHON \"$TESTDIR/dummyssh\"" ssh://user@dummy/doesnotexist
   pulling from ssh://user@dummy/doesnotexist
   remote: abort: repository doesnotexist not found!
   abort: no suitable response from remote hg!
@@ -156,7 +156,7 @@
 
 find incoming on the remote side
 
-  $ hg incoming -R ../remote -e "python \"$TESTDIR/dummyssh\"" ssh://user@dummy/local
+  $ hg incoming -R ../remote -e "$PYTHON \"$TESTDIR/dummyssh\"" ssh://user@dummy/local
   comparing with ssh://user@dummy/local
   searching for changes
   changeset:   3:a28a9d1a809c
@@ -169,7 +169,7 @@
 
 find incoming on the remote side (using absolute path)
 
-  $ hg incoming -R ../remote -e "python \"$TESTDIR/dummyssh\"" "ssh://user@dummy/`pwd`"
+  $ hg incoming -R ../remote -e "$PYTHON \"$TESTDIR/dummyssh\"" "ssh://user@dummy/`pwd`"
   comparing with ssh://user@dummy/$TESTTMP/local
   searching for changes
   changeset:   3:a28a9d1a809c
@@ -216,7 +216,7 @@
 test pushkeys and bookmarks
 
   $ cd ../local
-  $ hg debugpushkey --config ui.ssh="python \"$TESTDIR/dummyssh\"" ssh://user@dummy/remote namespaces
+  $ hg debugpushkey --config ui.ssh="$PYTHON \"$TESTDIR/dummyssh\"" ssh://user@dummy/remote namespaces
   bookmarks	
   namespaces	
   phases	
@@ -231,7 +231,7 @@
   no changes found
   exporting bookmark foo
   [1]
-  $ hg debugpushkey --config ui.ssh="python \"$TESTDIR/dummyssh\"" ssh://user@dummy/remote bookmarks
+  $ hg debugpushkey --config ui.ssh="$PYTHON \"$TESTDIR/dummyssh\"" ssh://user@dummy/remote bookmarks
   foo	1160648e36cec0054048a7edc4110c6f84fde594
   $ hg book -f foo
   $ hg push --traceback
@@ -311,7 +311,7 @@
   $ hg -R ../remote bookmark test
   $ hg -R ../remote bookmarks
    * test                      4:6c0482d977a3
-  $ hg clone -e "python \"$TESTDIR/dummyssh\"" ssh://user@dummy/remote local-bookmarks
+  $ hg clone -e "$PYTHON \"$TESTDIR/dummyssh\"" ssh://user@dummy/remote local-bookmarks
   requesting all changes
   adding changesets
   adding manifests
@@ -338,21 +338,21 @@
 
 Test remote paths with spaces (issue2983):
 
-  $ hg init --ssh "python \"$TESTDIR/dummyssh\"" "ssh://user@dummy/a repo"
+  $ hg init --ssh "$PYTHON \"$TESTDIR/dummyssh\"" "ssh://user@dummy/a repo"
   $ touch "$TESTTMP/a repo/test"
   $ hg -R 'a repo' commit -A -m "test"
   adding test
   $ hg -R 'a repo' tag tag
-  $ hg id --ssh "python \"$TESTDIR/dummyssh\"" "ssh://user@dummy/a repo"
+  $ hg id --ssh "$PYTHON \"$TESTDIR/dummyssh\"" "ssh://user@dummy/a repo"
   73649e48688a
 
-  $ hg id --ssh "python \"$TESTDIR/dummyssh\"" "ssh://user@dummy/a repo#noNoNO"
+  $ hg id --ssh "$PYTHON \"$TESTDIR/dummyssh\"" "ssh://user@dummy/a repo#noNoNO"
   abort: unknown revision 'noNoNO'!
   [255]
 
 Test (non-)escaping of remote paths with spaces when cloning (issue3145):
 
-  $ hg clone --ssh "python \"$TESTDIR/dummyssh\"" "ssh://user@dummy/a repo"
+  $ hg clone --ssh "$PYTHON \"$TESTDIR/dummyssh\"" "ssh://user@dummy/a repo"
   destination directory: a repo
   abort: destination 'a repo' is not empty
   [255]
@@ -543,11 +543,11 @@
 
   $ echo "pretxnchangegroup.fail = python:$TESTTMP/failhook:hook" >> remote/.hg/hgrc
 
-  $ hg -q --config ui.ssh="python $TESTDIR/dummyssh" clone ssh://user@dummy/remote hookout
+  $ hg -q --config ui.ssh="$PYTHON $TESTDIR/dummyssh" clone ssh://user@dummy/remote hookout
   $ cd hookout
   $ touch hookfailure
   $ hg -q commit -A -m 'remote hook failure'
-  $ hg --config ui.ssh="python $TESTDIR/dummyssh" push
+  $ hg --config ui.ssh="$PYTHON $TESTDIR/dummyssh" push
   pushing to ssh://user@dummy/remote
   searching for changes
   remote: adding changesets
@@ -569,7 +569,7 @@
   > [extensions]
   > crash = ${TESTDIR}/crashgetbundler.py
   > EOF
-  $ hg --config ui.ssh="python $TESTDIR/dummyssh" pull
+  $ hg --config ui.ssh="$PYTHON $TESTDIR/dummyssh" pull
   pulling from ssh://user@dummy/remote
   searching for changes
   remote: abort: this is an exercise

--- a/tests/test-subrepo-relative-path.t	Tue Jun 20 17:25:57 2017 -0400
+++ b/tests/test-subrepo-relative-path.t	Tue Jun 20 17:31:18 2017 -0400
@@ -74,7 +74,7 @@
 
 subrepo paths with ssh urls
 
-  $ hg clone -e "python \"$TESTDIR/dummyssh\"" ssh://user@dummy/cloned sshclone
+  $ hg clone -e "$PYTHON \"$TESTDIR/dummyssh\"" ssh://user@dummy/cloned sshclone
   requesting all changes
   adding changesets
   adding manifests
@@ -89,7 +89,7 @@
   added 1 changesets with 1 changes to 1 files
   3 files updated, 0 files merged, 0 files removed, 0 files unresolved
 
-  $ hg -R sshclone push -e "python \"$TESTDIR/dummyssh\"" ssh://user@dummy/`pwd`/cloned
+  $ hg -R sshclone push -e "$PYTHON \"$TESTDIR/dummyssh\"" ssh://user@dummy/`pwd`/cloned
   pushing to ssh://user@dummy/$TESTTMP/cloned
   pushing subrepo sub to ssh://user@dummy/$TESTTMP/sub
   searching for changes

--- a/tests/test-treemanifest.t	Tue Jun 20 17:25:57 2017 -0400
+++ b/tests/test-treemanifest.t	Tue Jun 20 17:31:18 2017 -0400
@@ -4,7 +4,7 @@
   > [format]
   > usegeneraldelta=yes
   > [ui]
-  > ssh=python "$TESTDIR/dummyssh"
+  > ssh=$PYTHON "$TESTDIR/dummyssh"
   > EOF
 
 Set up repo

--- a/tests/test-wireproto.t	Tue Jun 20 17:25:57 2017 -0400
+++ b/tests/test-wireproto.t	Tue Jun 20 17:31:18 2017 -0400
@@ -147,13 +147,13 @@
 
 SSH (try to exercise the ssh functionality with a dummy script):
 
-  $ hg debugwireargs --ssh "python $TESTDIR/dummyssh" ssh://user@dummy/repo uno due tre quattro
+  $ hg debugwireargs --ssh "$PYTHON $TESTDIR/dummyssh" ssh://user@dummy/repo uno due tre quattro
   uno due tre quattro None
-  $ hg debugwireargs --ssh "python $TESTDIR/dummyssh" ssh://user@dummy/repo eins zwei --four vier
+  $ hg debugwireargs --ssh "$PYTHON $TESTDIR/dummyssh" ssh://user@dummy/repo eins zwei --four vier
   eins zwei None vier None
-  $ hg debugwireargs --ssh "python $TESTDIR/dummyssh" ssh://user@dummy/repo eins zwei
+  $ hg debugwireargs --ssh "$PYTHON $TESTDIR/dummyssh" ssh://user@dummy/repo eins zwei
   eins zwei None None None
-  $ hg debugwireargs --ssh "python $TESTDIR/dummyssh" ssh://user@dummy/repo eins zwei --five fuenf
+  $ hg debugwireargs --ssh "$PYTHON $TESTDIR/dummyssh" ssh://user@dummy/repo eins zwei --five fuenf
   eins zwei None None None
 
 Explicitly kill daemons to let the test exit on Windows