util: introduce util.debugstacktrace for showing a stack trace without crashing
This is often very handy when hacking/debugging.
Calling util.debugstacktrace('hey') from a place in hg will give something like:
hey at:
./hg:38 in <module>
/home/user/hgsrc/mercurial/dispatch.py:28 in run
/home/user/hgsrc/mercurial/dispatch.py:65 in dispatch
/home/user/hgsrc/mercurial/dispatch.py:88 in _runcatch
/home/user/hgsrc/mercurial/dispatch.py:740 in _dispatch
/home/user/hgsrc/mercurial/dispatch.py:514 in runcommand
/home/user/hgsrc/mercurial/dispatch.py:830 in _runcommand
/home/user/hgsrc/mercurial/dispatch.py:801 in checkargs
/home/user/hgsrc/mercurial/dispatch.py:737 in <lambda>
/home/user/hgsrc/mercurial/util.py:472 in check
...
$ hg init t
$ cd t
$ echo This is file a1 > a
$ hg add a
$ hg commit -m "commit #0"
$ echo This is file b1 > b
$ hg add b
$ hg commit -m "commit #1"
$ rm b
$ hg update 0
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo This is file b2 > b
$ hg add b
$ hg commit -m "commit #2"
created new head
$ cd ..; rm -r t
$ mkdir t
$ cd t
$ hg init
$ echo This is file a1 > a
$ hg add a
$ hg commit -m "commit #0"
$ echo This is file b1 > b
$ hg add b
$ hg commit -m "commit #1"
$ rm b
$ hg update 0
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo This is file b2 > b
$ hg commit -A -m "commit #2"
adding b
created new head
$ cd ..; rm -r t
$ hg init t
$ cd t
$ echo This is file a1 > a
$ hg add a
$ hg commit -m "commit #0"
$ echo This is file b1 > b
$ hg add b
$ hg commit -m "commit #1"
$ rm b
$ hg remove b
$ hg update 0
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo This is file b2 > b
$ hg commit -A -m "commit #2"
adding b
created new head
$ cd ..