`git difftool -d` with Beyond Compare 4: cannot spawn .git/hooks/virtual-filesystem: No such file or directory #13

wilbaker · 2018-07-31T20:57:35Z

I was not able to find an open or closed issue matching what I'm seeing

Setup

Which version of Git for Windows are you using? Is it 32-bit or 64-bit?

64-bit

$ git --version --build-options

git version 2.17.1.gvfs.2.1.6.gdc051a1
cpu: x86_64
built from commit: dc051a1f5beb8ce0b22051afd9be86a0541a534a
sizeof-long: 4

Which version of Windows are you running? Vista, 7, 8, 10? Is it 32-bit or 64-bit?

64-bit Windows 10

What options did you set as part of the installation? Or did you choose the
defaults?

# One of the following:
> type "C:\Program Files\Git\etc\install-options.txt"
> type "C:\Program Files (x86)\Git\etc\install-options.txt"
> type "%USERPROFILE%\AppData\Local\Programs\Git\etc\install-options.txt"
$ cat /etc/install-options.txt

M:\>type "C:\Program Files\Git\etc\install-options.txt"
Editor Option: VIM
Path Option: Cmd
SSH Option: OpenSSH
CURL Option: OpenSSL
CRLF Option: CRLFAlways
Bash Terminal Option: MinTTY
Performance Tweaks FSCache: Enabled
Use Credential Manager: Enabled
Enable Symlinks: Disabled

Any other interesting things about your environment that might be related
to the issue you're seeing?

This is with a VFSForGit repo.

Details

Which terminal/shell are you running Git from? e.g Bash/CMD/PowerShell/other

CMD

What commands did you run to trigger this issue? If you can provide a
Minimal, Complete, and Verifiable example
this will help us understand the issue.

<modify some files>
git difftool -d

What did you expect to occur after running these commands?

Beyond Compare 4 would launch, and allow me to modify and save source files.

What actually happened instead?

Beyond Compare 4 launched, but changes made in the right pane were lost (and the error message below was displayed).

M:\gvfsDiffTest2\src>git difftool -d
error: cannot spawn .git/hooks/virtual-filesystem: No such file or directory
fatal: unable to load virtual file system
fatal: diff-files did not exit properly

If the problem was occurring with a specific repository, can you provide the
URL to that repository to help us with testing?

This is not repo specific, but is specific to using VFSForGit.

The text was updated successfully, but these errors were encountered:

…x has been redirected Fixes #13 Some git commands spawn helpers and redirect the index to a different location. These include "difftool -d" and the sequencer (i.e. `git rebase -i`, `git cherry-pick` and `git revert`) and others. In those instances we don't want to update their temporary index with our virtualization data. Helped-by: Johannes Schindelin <[email protected]> Signed-off-by: Ben Peart <[email protected]>

…x has been redirected Fixes microsoft#13 Some git commands spawn helpers and redirect the index to a different location. These include "difftool -d" and the sequencer (i.e. `git rebase -i`, `git cherry-pick` and `git revert`) and others. In those instances we don't want to update their temporary index with our virtualization data. Helped-by: Johannes Schindelin <[email protected]> Signed-off-by: Ben Peart <[email protected]>

…x has been redirected Fixes #13 Some git commands spawn helpers and redirect the index to a different location. These include "difftool -d" and the sequencer (i.e. `git rebase -i`, `git cherry-pick` and `git revert`) and others. In those instances we don't want to update their temporary index with our virtualization data. Helped-by: Johannes Schindelin <[email protected]> Signed-off-by: Ben Peart <[email protected]>

The `linux-leaks` job has become a lot more aggressive, failing the following test cases: - t0001.52 extensions.objectFormat is not allowed with repo version 0 - t1302.3 gitdir selection on unsupported repo - t1302.4 gitdir not required mode - t1302.5 gitdir required mode - t1302.9 abort version=1 no-such-extension - t1302.12 abort version=0 noop-v1 The reason is that the `commondir` strbuf _is_ sometimes initialized _even if_ `discover_git_directory()` fails. The symptom: Direct leak of 24 byte(s) in 1 object(s) allocated from: #0 0x7f2e80ed8293 in __interceptor_realloc ../../../../src/libsanitizer/lsan/lsan_interceptors.cpp:98 #1 0x5603ff6ae674 in xrealloc wrapper.c:138 #2 0x5603ff661801 in strbuf_grow strbuf.c:101 #3 0x5603ff662417 in strbuf_add strbuf.c:300 #4 0x5603ff653e2b in strbuf_addstr strbuf.h:310 #5 0x5603ff65703b in setup_git_directory_gently_1 setup.c:1329 #6 0x5603ff65731b in discover_git_directory_reason setup.c:1388 #7 0x5603ff55b6c0 in discover_git_directory setup.h:79 #8 0x5603ff55b7ce in hook_path_early hook.c:35 #9 0x5603ff55b97d in find_hook hook.c:77 #10 0x5603ff55bcd3 in run_hooks_opt hook.c:189 #11 0x5603ff37ca05 in run_pre_command_hook git.c:457 #12 0x5603ff37ce0a in run_builtin git.c:532 #13 0x5603ff37d37e in handle_builtin git.c:798 #14 0x5603ff37d65a in run_argv git.c:867 #15 0x5603ff37dc8e in cmd_main git.c:1007 #16 0x5603ff48f4ee in main common-main.c:62 #17 0x7f2e80cabd8f in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58 The fix is easy: always release the `strbuf`s, even when the discovery of the Git directory failed. Signed-off-by: Johannes Schindelin <[email protected]>

…x has been redirected Fixes #13 Some git commands spawn helpers and redirect the index to a different location. These include "difftool -d" and the sequencer (i.e. `git rebase -i`, `git cherry-pick` and `git revert`) and others. In those instances we don't want to update their temporary index with our virtualization data. Helped-by: Johannes Schindelin <[email protected]> Signed-off-by: Ben Peart <[email protected]>

An internal customer reported a segfault when running `git sparse-checkout set` with the `index.sparse` config enabled. I was unable to reproduce it locally, but with their help we debugged into the failing process and discovered the following stacktrace: ``` #0 0x00007ff6318fb7b0 in rehash (map=0x3dfb00d0440, newsize=1048576) at hashmap.c:125 #1 0x00007ff6318fbc66 in hashmap_add (map=0x3dfb00d0440, entry=0x3dfb5c58bc8) at hashmap.c:247 #2 0x00007ff631937a70 in hash_index_entry (istate=0x3dfb00d0400, ce=0x3dfb5c58bc8) at name-hash.c:122 #3 0x00007ff631938a2f in add_name_hash (istate=0x3dfb00d0400, ce=0x3dfb5c58bc8) at name-hash.c:638 #4 0x00007ff631a064de in set_index_entry (istate=0x3dfb00d0400, nr=8291, ce=0x3dfb5c58bc8) at sparse-index.c:255 #5 0x00007ff631a06692 in add_path_to_index (oid=0x5ff130, base=0x5ff580, path=0x3dfb4b725da "<redacted>", mode=33188, context=0x5ff570) at sparse-index.c:307 #6 0x00007ff631a3b48c in read_tree_at (r=0x7ff631c026a0 <the_repo>, tree=0x3dfb5b41f60, base=0x5ff580, depth=2, pathspec=0x5ff5a0, fn=0x7ff631a064e5 <add_path_to_index>, context=0x5ff570) at tree.c:46 #7 0x00007ff631a3b60b in read_tree_at (r=0x7ff631c026a0 <the_repo>, tree=0x3dfb5b41e80, base=0x5ff580, depth=1, pathspec=0x5ff5a0, fn=0x7ff631a064e5 <add_path_to_index>, context=0x5ff570) at tree.c:80 #8 0x00007ff631a3b60b in read_tree_at (r=0x7ff631c026a0 <the_repo>, tree=0x3dfb5b41ac8, base=0x5ff580, depth=0, pathspec=0x5ff5a0, fn=0x7ff631a064e5 <add_path_to_index>, context=0x5ff570) at tree.c:80 #9 0x00007ff631a06a95 in expand_index (istate=0x3dfb00d0100, pl=0x0) at sparse-index.c:422 #10 0x00007ff631a06cbd in ensure_full_index (istate=0x3dfb00d0100) at sparse-index.c:456 #11 0x00007ff631990d08 in index_name_stage_pos (istate=0x3dfb00d0100, name=0x3dfb0020080 "algorithm/levenshtein", namelen=21, stage=0, search_mode=EXPAND_SPARSE) at read-cache.c:556 #12 0x00007ff631990d6c in index_name_pos (istate=0x3dfb00d0100, name=0x3dfb0020080 "algorithm/levenshtein", namelen=21) at read-cache.c:566 #13 0x00007ff63180dbb5 in sanitize_paths (argc=185, argv=0x3dfb0030018, prefix=0x0, skip_checks=0) at builtin/sparse-checkout.c:756 #14 0x00007ff63180de50 in sparse_checkout_set (argc=185, argv=0x3dfb0030018, prefix=0x0) at builtin/sparse-checkout.c:860 #15 0x00007ff63180e6c5 in cmd_sparse_checkout (argc=186, argv=0x3dfb0030018, prefix=0x0) at builtin/sparse-checkout.c:1063 #16 0x00007ff6317234cb in run_builtin (p=0x7ff631ad9b38 <commands+2808>, argc=187, argv=0x3dfb0030018) at git.c:548 #17 0x00007ff6317239c0 in handle_builtin (argc=187, argv=0x3dfb0030018) at git.c:808 #18 0x00007ff631723c7d in run_argv (argcp=0x5ffdd0, argv=0x5ffd78) at git.c:877 #19 0x00007ff6317241d1 in cmd_main (argc=187, argv=0x3dfb0030018) at git.c:1017 #20 0x00007ff631838b60 in main (argc=190, argv=0x3dfb0030000) at common-main.c:64 ``` The very bottom of the stack being the `rehash()` method from `hashmap.c` as called within the `name-hash` API made me look at where these hashmaps were being used in the sparse index logic. These were being copied across indexes, which seems dangerous. Indeed, clearing these hashmaps and setting them as not initialized fixes the segfault. The second commit is a response to a test failure that happens in `t1092-sparse-checkout-compatibility.sh` where `git stash pop` starts to fail because the underlying `git checkout-index` process fails due to colliding files. Passing the `-f` flag appears to work, but it's unclear why this name-hash change causes that change in behavior.

wilbaker assigned benpeart Jul 31, 2018

benpeart mentioned this issue Aug 2, 2018

virtualfilesystem: don't run the virtual file system hook if the index has been redirected #15

Merged

benpeart closed this as completed in #15 Aug 20, 2018

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`git difftool -d` with Beyond Compare 4: cannot spawn .git/hooks/virtual-filesystem: No such file or directory #13

`git difftool -d` with Beyond Compare 4: cannot spawn .git/hooks/virtual-filesystem: No such file or directory #13

wilbaker commented Jul 31, 2018

git difftool -d with Beyond Compare 4: cannot spawn .git/hooks/virtual-filesystem: No such file or directory #13

git difftool -d with Beyond Compare 4: cannot spawn .git/hooks/virtual-filesystem: No such file or directory #13

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wilbaker commented Jul 31, 2018

Setup

Details

`git difftool -d` with Beyond Compare 4: cannot spawn .git/hooks/virtual-filesystem: No such file or directory #13

`git difftool -d` with Beyond Compare 4: cannot spawn .git/hooks/virtual-filesystem: No such file or directory #13