windows: degrade to py2 behavior when reading a non-symlink as a symlink
While waiting for the push to hg-committed in WSL to complete, I ran a
`phabimport` from Windows and got this traceback:
$ hg phabimport 11313
** Unknown exception encountered with possibly-broken third-party extension "mercurial_keyring" (version N/A)
** which supports versions unknown of Mercurial.
** Please disable "mercurial_keyring" and try your action again.
** If that fixes the bug please report it to https://foss.heptapod.net/mercurial/mercurial_keyring/issues
** Python 3.9.5 (default, May 6 2021, 17:29:31) [MSC v.1928 64 bit (AMD64)]
** Mercurial Distributed SCM (version 5.9rc1+hg32.
0e2f5733563d)
** Extensions loaded: absorb, blackbox, evolve 10.3.3, extdiff, fastannotate, fix, mercurial_keyring, mq, phabblocker
20210126, phabricator, rebase, show, strip, topic 0.22.3
Traceback (most recent call last):
File "mercurial.lock", line 279, in _trylock
File "mercurial.vfs", line 202, in makelock
File "mercurial.util", line 2147, in makelock
FileExistsError: [WinError 183] Cannot create a file when that file already exists: b'hp-omen:78348' -> b'C:\\Users\\Matt\\hg/.hg/store/lock'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "<string>", line 24, in <module>
File "mercurial.dispatch", line 144, in run
File "mercurial.dispatch", line 250, in dispatch
File "mercurial.dispatch", line 294, in _rundispatch
File "mercurial.dispatch", line 470, in _runcatch
File "mercurial.dispatch", line 480, in _callcatch
File "mercurial.scmutil", line 153, in callcatch
File "mercurial.dispatch", line 460, in _runcatchfunc
File "mercurial.dispatch", line 1273, in _dispatch
File "mercurial.dispatch", line 918, in runcommand
File "mercurial.dispatch", line 1285, in _runcommand
File "mercurial.dispatch", line 1271, in <lambda>
File "mercurial.util", line 1886, in check
File "mercurial.util", line 1886, in check
File "hgext.mq", line 4239, in mqcommand
File "mercurial.util", line 1886, in check
File "mercurial.util", line 1886, in check
File "hgext.phabricator", line 314, in inner
File "hgext.phabricator", line 2222, in phabimport
File "hgext.phabricator", line 2123, in readpatch
File "hgext.phabricator", line 2199, in _write
File "mercurial.localrepo", line 2956, in lock
File "mercurial.localrepo", line 2918, in _lock
File "mercurial.lock", line 152, in trylock
File "mercurial.lock", line 283, in _trylock
File "mercurial.lock", line 314, in _readlock
File "mercurial.vfs", line 221, in readlock
File "mercurial.util", line 2163, in readlock
File "mercurial.windows", line 619, in readlink
ValueError: not a symbolic link
Both exceptions look accurate (the file exists, and the Windows side can't read
WSL side symlinks). I didn't try to reproduce this entirely within the Windows
side, but we can do better than a cryptic stacktrace. With this change, the
same scenario results in this abort:
abort: C:\Users\Matt\hg/.hg/store/lock: The file cannot be accessed by the system
When both the `push` and `phabimport` are done on the Windows side, it prints a
message about waiting for the lock, and successfully applies the patch after the
push completes.
I'm not sure if there's enough info to be able to convert the abort into the
wait scenario. As it stands now, we don't support symlinks on Windows, which
requires either a UAC Administrator level process or an opt-in in developer
mode, and there are several places where the new symlink on Windows support in
py3 was explicitly disabled in order to get tests to pass quicker.
Differential Revision: https://phab.mercurial-scm.org/D11333
$ cat >> $HGRCPATH << EOF
> [ui]
> ssh = "$PYTHON" "$TESTDIR/dummyssh"
> [extensions]
> fastannotate=
> [fastannotate]
> mainbranch=@
> EOF
setup the server repo
$ hg init repo-server
$ cd repo-server
$ cat >> .hg/hgrc << EOF
> [fastannotate]
> server=1
> EOF
$ for i in 1 2 3 4; do
> echo $i >> a
> hg commit -A -m $i a
> done
$ [ -d .hg/fastannotate ]
[1]
$ hg bookmark @
$ cd ..
setup the local repo
$ hg clone 'ssh://user@dummy/repo-server' repo-local -q
$ cd repo-local
$ cat >> .hg/hgrc << EOF
> [fastannotate]
> client=1
> clientfetchthreshold=0
> EOF
$ [ -d .hg/fastannotate ]
[1]
$ hg fastannotate a --debug
running * (glob)
sending hello command
sending between command
remote: * (glob) (?)
remote: capabilities: * (glob)
remote: * (glob) (?)
sending protocaps command
fastannotate: requesting 1 files
sending getannotate command
fastannotate: writing 112 bytes to fastannotate/default/a.l
fastannotate: writing 94 bytes to fastannotate/default/a.m
fastannotate: a: using fast path (resolved fctx: True)
0: 1
1: 2
2: 3
3: 4
the cache could be reused and no download is necessary
$ hg fastannotate a --debug
fastannotate: a: using fast path (resolved fctx: True)
0: 1
1: 2
2: 3
3: 4
if the client agrees where the head of the master branch is, no re-download
happens even if the client has more commits
$ echo 5 >> a
$ hg commit -m 5
$ hg bookmark -r 3 @ -f
$ hg fastannotate a --debug
0: 1
1: 2
2: 3
3: 4
4: 5
if the client has a different "@" (head of the master branch) and "@" is ahead
of the server, the server can detect things are unchanged and does not return
full contents (not that there is no "writing ... to fastannotate"), but the
client can also build things up on its own (causing diverge)
$ hg bookmark -r 4 @ -f
$ hg fastannotate a --debug
running * (glob)
sending hello command
sending between command
remote: * (glob) (?)
remote: capabilities: * (glob)
remote: * (glob) (?)
sending protocaps command
fastannotate: requesting 1 files
sending getannotate command
fastannotate: a: 1 new changesets in the main branch
0: 1
1: 2
2: 3
3: 4
4: 5
if the client has a different "@" which is behind the server. no download is
necessary
$ hg fastannotate a --debug --config fastannotate.mainbranch=2
fastannotate: a: using fast path (resolved fctx: True)
0: 1
1: 2
2: 3
3: 4
4: 5
define fastannotate on-disk paths
$ p1=.hg/fastannotate/default
$ p2=../repo-server/.hg/fastannotate/default
revert bookmark change so the client is behind the server
$ hg bookmark -r 2 @ -f
in the "fctx" mode with the "annotate" command, the client also downloads the
cache. but not in the (default) "fastannotate" mode.
$ rm $p1/a.l $p1/a.m
$ hg annotate a --debug | grep 'fastannotate: writing'
[1]
$ hg annotate a --config fastannotate.modes=fctx --debug | grep 'fastannotate: writing' | sort
fastannotate: writing 112 bytes to fastannotate/default/a.l
fastannotate: writing 94 bytes to fastannotate/default/a.m
the fastannotate cache (built server-side, downloaded client-side) in two repos
have the same content (because the client downloads from the server)
$ diff $p1/a.l $p2/a.l
$ diff $p1/a.m $p2/a.m
in the "fctx" mode, the client could also build the cache locally
$ hg annotate a --config fastannotate.modes=fctx --debug --config fastannotate.mainbranch=4 | grep fastannotate
fastannotate: requesting 1 files
fastannotate: a: 1 new changesets in the main branch
the server would rebuild broken cache automatically
$ cp $p2/a.m $p2/a.m.bak
$ echo BROKEN1 > $p1/a.m
$ echo BROKEN2 > $p2/a.m
$ hg fastannotate a --debug | grep 'fastannotate: writing' | sort
fastannotate: writing 112 bytes to fastannotate/default/a.l
fastannotate: writing 94 bytes to fastannotate/default/a.m
$ diff $p1/a.m $p2/a.m
$ diff $p2/a.m $p2/a.m.bak
use the "debugbuildannotatecache" command to build annotate cache
$ rm -rf $p1 $p2
$ hg --cwd ../repo-server debugbuildannotatecache a --debug
fastannotate: a: 4 new changesets in the main branch
$ hg --cwd ../repo-local debugbuildannotatecache a --debug
running * (glob)
sending hello command
sending between command
remote: * (glob) (?)
remote: capabilities: * (glob)
remote: * (glob) (?)
sending protocaps command
fastannotate: requesting 1 files
sending getannotate command
fastannotate: writing * (glob)
fastannotate: writing * (glob)
$ diff $p1/a.l $p2/a.l
$ diff $p1/a.m $p2/a.m
with the clientfetchthreshold config option, the client can build up the cache
without downloading from the server
$ rm -rf $p1
$ hg fastannotate a --debug --config fastannotate.clientfetchthreshold=10
fastannotate: a: 3 new changesets in the main branch
0: 1
1: 2
2: 3
3: 4
4: 5
if the fastannotate directory is not writable, the fctx mode still works
$ rm -rf $p1
$ touch $p1
$ hg annotate a --debug --traceback --config fastannotate.modes=fctx
fastannotate: a: cache broken and deleted
fastannotate: prefetch failed: * (glob)
fastannotate: a: cache broken and deleted
fastannotate: falling back to the vanilla annotate: * (glob)
0: 1
1: 2
2: 3
3: 4
4: 5
with serverbuildondemand=False, the server will not build anything
$ cat >> ../repo-server/.hg/hgrc <<EOF
> [fastannotate]
> serverbuildondemand=False
> EOF
$ rm -rf $p1 $p2
$ hg fastannotate a --debug | grep 'fastannotate: writing'
[1]