--- a/tests/test-chg.t	Sat May 07 00:16:58 2016 +0100
+++ b/tests/test-chg.t	Fri May 06 23:57:56 2016 +0100
@@ -10,3 +10,23 @@
   $ hg status
   hg: parse error at * (glob)
   [255]
+
+alias having an environment variable and set to use pager
+
+  $ rm $HGRCPATH
+  $ cat >> $HGRCPATH <<'EOF'
+  > [ui]
+  > formatted = yes
+  > [extensions]
+  > pager =
+  > [pager]
+  > pager = sed -e 's/^/P/'
+  > attend = printa
+  > [alias]
+  > printa = log -T "$A\n" -r 0
+  > EOF
+
+  $ A=1 hg printa
+  P1
+  $ A=2 hg printa
+  P2