symlink issue in 2.49.0.windows.1

symlink issue in 2.49.0.windows.1

[Conti, Chris]

What did you do before the bug happened? (Steps to reproduce your issue)
I have an alias that enables core.symlinks from the command line:

relevant lines from my system gitconfig:
core.symlinks=false

relevant lines from my user .gitconfig:
difftool.bc4diredit.cmd="c:/Program Files/Beyond Compare 4/BCompare.exe" -lro -expandall -solo "$LOCAL" "$REMOTE"
alias.diffdirsym=-c core.symlinks=true difftool --dir-diff --tool=bc4diredit --no-prompt

execution (in a repo with a changed file)
git diffdirsym

execution environment
elevated powershell 5.1 shell

What did you expect to happen? (Expected behavior)

for the command to work

What happened instead? (Actual behavior)

received a "Function not implemented" error:
error: could not symlink '<redacted physical path to changed file>' to 'C:\Users\contc\AppData\Local\Temp/git-difftool.a49272/right/<redacted relative path to copy of changed file>': Function not implemented

What's different between what you expected and what actually happened?

Anything else you want to add:

verified the alias works in 2.48.1.windows.1

Please review the rest of the bug report below.
You can delete any lines you don't wish to share.


[System Info]
git version:
git version 2.49.0.windows.1
cpu: x86_64
built from commit: cca1f38702730b35f52c29efd62864b85e85ddcc
sizeof-long: 4
sizeof-size_t: 8
shell-path: D:/git-sdk-64-build-installers/usr/bin/sh
feature: fsmonitor--daemon
libcurl: 8.12.1
OpenSSL: OpenSSL 3.2.4 11 Feb 2025
zlib: 1.3.1
uname: Windows 10.0 19045
compiler info: gnuc: 14.2
libc info: no libc information available
$SHELL (typically, interactive shell): <unset>


[Enabled Hooks]

Chris Conti
Email: chris.conti@pega.com | pega.com

Re: symlink issue in 2.49.0.windows.1

[Johannes Schindelin]

hi Chris,

On Fri, 16 May 2025, Conti, Chris wrote:

> What did you do before the bug happened? (Steps to reproduce your issue)
> I have an alias that enables core.symlinks from the command line:
> 
> relevant lines from my system gitconfig:
> core.symlinks=false

Is this also the value `git config get --show-origin core.symlinks`
reports?

> 
> relevant lines from my user .gitconfig:
> difftool.bc4diredit.cmd="c:/Program Files/Beyond Compare 4/BCompare.exe" -lro -expandall -solo "$LOCAL" "$REMOTE"
> alias.diffdirsym=-c core.symlinks=true difftool --dir-diff --tool=bc4diredit --no-prompt
> 
> execution (in a repo with a changed file)
> git diffdirsym
> 
> execution environment
> elevated powershell 5.1 shell
> 
> What did you expect to happen? (Expected behavior)
> 
> for the command to work
> 
> What happened instead? (Actual behavior)
> 
> received a "Function not implemented" error:
> error: could not symlink '<redacted physical path to changed file>' to 'C:\Users\contc\AppData\Local\Temp/git-difftool.a49272/right/<redacted relative path to copy of changed file>': Function not implemented

This looks very similar to the report in
https://github.com/git-for-windows/git/issues/5517 (which I am constantly
running out of time to help with, maybe you can?).

The culprit identified in this ticket is 8241ae63d821 (difftool: eliminate
use of global variables, 2025-02-05) which seems to have flipped the
default of `--symlinks` inadvertently (as far as Windows is concerned,
that is).

Ciao,
Johannes

> 
> What's different between what you expected and what actually happened?
> 
> Anything else you want to add:
> 
> verified the alias works in 2.48.1.windows.1
> 
> Please review the rest of the bug report below.
> You can delete any lines you don't wish to share.
> 
> 
> [System Info]
> git version:
> git version 2.49.0.windows.1
> cpu: x86_64
> built from commit: cca1f38702730b35f52c29efd62864b85e85ddcc
> sizeof-long: 4
> sizeof-size_t: 8
> shell-path: D:/git-sdk-64-build-installers/usr/bin/sh
> feature: fsmonitor--daemon
> libcurl: 8.12.1
> OpenSSL: OpenSSL 3.2.4 11 Feb 2025
> zlib: 1.3.1
> uname: Windows 10.0 19045
> compiler info: gnuc: 14.2
> libc info: no libc information available
> $SHELL (typically, interactive shell): <unset>
> 
> 
> [Enabled Hooks]
> 
> Chris Conti
> Email: chris.conti@pega.com | pega.com
> 
> 
>