External Diff Fails with Error: "fatal: invalid filter-spec"

[tapiester]

Starting today (I may have just upgraded to 2.8.2.0, or it might have been several days ago), Fork fails to display external diffs with the message:

Git Error
An unexpected error occurred while performing the git request

fatal: invalid filter-spec '<commit-sha>:<path-to-file>'

Note that <commit-sha> and <path-to-file> above are placeholders and not the literal error text.

[DanPristupov]

Did you switch Fork to some other git instance?

[tapiester]

No, it's always been using the system git instance, though that was upgraded to 2.50.0 recently as well

[DanPristupov]

Try to switch Fork to the internal git.

[tapiester]

Internal git is still able to launch external diffs, so I suppose the issue is specific to system git use.

[0xworks]

Same here.
Fork 2.9.0.0. Using external git instance (2.50.0) gives "invalid filter-spec" when trying to view external diff.
It's fine when using internal git instance (currently 2.47.1)

[DanPristupov]

This is a regression in cat-file in git 2.50:

$ git version
git version 2.47.1.windows.2

$ git cat-file --filter "8328b92:ChangeLog.md"
<content>

$ git version
git version 2.50.0.windows.1

$ git cat-file --filter "8328b92:Changelog.md"
fatal: invalid filter-spec '8328b92:Changelog.md'

[tapiester]

This is a regression in cat-file in git 2.50:

$ git version
git version 2.47.1.windows.2

$ git cat-file --filter "8328b92:ChangeLog.md"
<content>

$ git version
git version 2.50.0.windows.1

$ git cat-file --filter "8328b92:Changelog.md"
fatal: invalid filter-spec '8328b92:Changelog.md'

Is this a regression with Fork's use of cat-file or in Git's implementation of it? Just wondering if I should be looking out for a patch to Fork or Git.

[DanPristupov]

To my surprise this was caused by a typo in Fork. cat-file --filter had been working properly for many-many years until 2.50.

https://public-inbox.org/git/9b3623a9-b596-44bc-b267-499e568a7f60@gmail.com/T/#me5c2d2834b1656e1d85b7b857e5f2ab879f1ec8b

So, you should wait for Fork 2.10

[isanych]

How to switch to local instance? Settings window does not allow to select it, clicking instance selection does nothing, combobox does not expand:

logs shows that fork sees both instances

🔷 2025-07-03 09:47:41.105 Running 'C:\opt\apps\git\current\bin\git.exe version'
🔷 2025-07-03 09:47:41.141 Running 'C:\Users\Administrator\AppData\Local\Fork\gitInstance\2.47.1.2\bin\git.exe version'
🔷 2025-07-03 09:47:41.183 Git Location: C:\opt\apps\git\current\bin\git.exe

Modifying settings.json from None to:

  "GitInstancePath": "C:\\Users\\Administrator\\AppData\\Local\\Fork\\gitInstance\\2.47.1.2\\bin\\git.exe",

also not helping. Is changing system git is the only way?

[DanPristupov]

1. The combobox must be active. Try to restart the application.
2. Or set "GitInstancePath": null, in %localappdata%\Fork\settings.json

[isanych]

I've restarted fork multiple times, I've even reinstalled it (I can only download 2.8.2 installer and then update it 2.9.0), setting "GitInstancePath": null not helping, I guess it is easier to change system git now

[DanPristupov]

Ah, I see you used forkgitinstance ENV variable. I even forgot it exists.

[isanych]

After removing that variable I'm able to switch to internal instance and use diff again, thanks