Homebrew-core: Mojave: Git uses broken tcl-tk (proposed workaround)

[arichardson]

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---

I would have commented on the existing issue but since it has been locked I have to create a new issue instead.

Since it is not acceptable to add a tcl-tk dependency on git, I propose to detect the presence of homebrew tcl-tk when running git-gui and using the correct wish binary then.
Would such a patch be acceptable?

I have worked around the broken git-gui dialog boxes by editing the libexec/git-core/git-gui script to invoke homebrew wish instead of the system one. I tried changing the wish binary that is invoked to /usr/local/opt/tcl-tk/bin/wish instead but that gave me some errors. Therefore I add a symlink to the tcl-tk wish binary inside the share/git-gui/lib/Git Gui.app/Contents/MacOS/Wish.homebrew directory and invoke that instead of share/git-gui/lib/Git Gui.app/Contents/MacOS/Wish.

Having to create the symlink inside share/git-gui/lib/Git Gui.app/Contents/MacOS/ is not ideal but I can't think of a better solution right now that doesn't add the tcl-tk dependency.

Fixed git-gui (which produces a working dialog box if tcl-tk is installed and an empty window if tcl-tk is missing:

#!/bin/sh
if test "z$*" = zversion ||
   test "z$*" = z--version
then
    echo 'git-gui version 0.21.GITGUI'
else
    libdir="${GIT_GUI_LIB_DIR:-/usr/local/Cellar/git/2.21.0/share/git-gui/lib}"
    wish="$libdir/Git Gui.app/Contents/MacOS/Wish"
    if [ -e "$wish.homebrew" ]; then
        echo "Using homebrew version of tcl-tk"
        wish="$wish.homebrew";
    elif [ -e "$(brew --prefix tcl-tk)/bin/wish" ]; then
        echo "Creating Wish.homebrew link in Git Gui.app to work around https://github.com/Homebrew/homebrew-core/issues/36390"
        ln -sf "$(brew --prefix tcl-tk)/bin/wish" "$wish.homebrew"
        wish="$wish.homebrew"
    else
        echo "WARNING: git-gui is probably using the broken macOS tcl-tk"
    fi
    exec "$wish" "$0" "$@"
fi

[MikeMcQuaid]

Since it is not acceptable to add a tcl-tk dependency on git, I propose to detect the presence of homebrew tcl-tk when running git-gui and using the correct wish binary then.
Would such a patch be acceptable?

It's hard to say without reviewing a pull request but: perhaps. Could you create one and CC me? Thanks!

[walski]

@arichardson is there still progress on this? Can I help in any way?

[arichardson]

@walski I haven't had time in the last few weeks to work on this. I haven't looked at the git formula in detail but I think it shouldn't be too hard to edit the libexec/git-core/git-gui either after install or before the build.

[MikeMcQuaid]

There is some related discussion in https://github.com/Homebrew/homebrew-core/issues/41338.

wish="$libdir/Git Gui.app/Contents/MacOS/Wish"

https://docs.brew.sh/Acceptable-Formulae#stuff-that-builds-an-app is worth noting here.

I would suggest we remove git-gui if it's not functional (and gitk if that applies too) and they could be a cask instead. We should add caveats if we do this and point people in the right direction to an alternative (e.g. brew cask install fork for a decent alternative).

[arichardson]

@MikeMcQuaid https://github.com/Homebrew/homebrew-core/pull/42789 removes the .app, but still keeps git-gui functional. Is that an acceptable solution?

[jasonkenneth]

This would be great to get to work! I just upgraded to Catalina, and I'm getting the warning that Tcl/Tk will probably be removed from MacOSX.

DEPRECATION WARNING: The system version of Tk is deprecated and may be removed in a future release. Please don't rely on it. Set TK_SILENCE_DEPRECATION=1 to suppress this warning.

[iMichka]

This whole discussion seems to have stalled ... We found no common ground for a fix. Different things have been proposed but right now nothing looks maintainable by our team. I'll just close this, and we will leave the situation as-is.

Tcl-tk is being phased out from mac, I agree. But we really can't add the homebrew tcl-tk dependency to git.

Maybe a solution would be to have second git formula, called git-tcl-tk, with the needed bells and whistles, for those who really need it.