signing with login shell

[Byron]

Use a login shell for spawning the programs to sign a buffer.

Related to #5839 and #5022.

Tasks

• cleanup
• use shell for any invocation
• use login shell
• additional fix: use gix for all Git configuration

Notes for the Reviewer

• I did some testing regarding signing, and the UI picking up signing related configuration, but that probably didn't run all the codepaths that changed.
• Fetching git configuration (one key at a time like the UI does) is now about 25% to 40% slower, at ~120microseconds. Still within the range I think.

Research

Environment variables in a release application

Launching a release application on MacOS (through the finder) yields the following environment variables.

  (
        "TMPDIR",
        "/var/folders/x7/jgy95vjs3v3ffszwn0wg0gz80000gn/T/",
    ),
    (
        "__CFBundleIdentifier",
        "com.apple.Terminal",
    ),
    (
        "XPC_FLAGS",
        "0x0",
    ),
    (
        "TERM",
        "xterm-256color",
    ),
    (
        "SSH_AUTH_SOCK",
        "/Users/byron/.gnupg/S.gpg-agent.ssh",
    ),
    (
        "XPC_SERVICE_NAME",
        "0",
    ),
    (
        "TERM_PROGRAM",
        "Apple_Terminal",
    ),
    (
        "TERM_PROGRAM_VERSION",
        "455",
    ),
    (
        "TERM_SESSION_ID",
        "<redacted>",
    ),
    (
        "SHELL",
        "/bin/zsh",
    ),
    (
        "HOME",
        "/Users/byron",
    ),
    (
        "LOGNAME",
        "byron",
    ),
    (
        "USER",
        "byron",
    ),
    (
        "PATH",
        "<redacted, but looks complete>",
    ),
    (
        "SHLVL",
        "1",
    ),
    (
        "PWD",
        "/Users/byron",
    ),
    (
        "OLDPWD",
        "/Users/byron",
    ),
    (
        "ZSH",
        "/Users/byron/.oh-my-zsh",
    ),
    (
        "PAGER",
        "less",
    ),
    (
        "LESS",
        "-R",
    ),
    (
        "LSCOLORS",
        "Gxfxcxdxbxegedabagacad",
    ),
    (
        "LS_COLORS",
        "di=1;36:ln=35:so=32:pi=33:ex=31:bd=34;46:cd=34;43:su=30;41:sg=30;46:tw=30;42:ow=30;43",
    ),
    (
        "HOMEBREW_PREFIX",
        "/opt/homebrew",
    ),
    (
        "HOMEBREW_CELLAR",
        "/opt/homebrew/Cellar",
    ),
    (
        "HOMEBREW_REPOSITORY",
        "/opt/homebrew",
    ),
    (
        "INFOPATH",
        "/opt/homebrew/share/info:/opt/homebrew/share/info:",
    ),
    (
        "GPG_TTY",
        "/dev/ttys005",
    ),
    (
        "EDITOR",
        "hx",
    ),
    (
        "BAT_THEME",
        "TwoDark",
    ),
    (
        "STARSHIP_SHELL",
        "zsh",
    ),
    (
        "STARSHIP_SESSION_KEY",
    ),
    (
        "HOMEBREW_NO_ANALYTICS",
        "1",
    ),
    (
        "LC_CTYPE",
        "UTF-8",
    ),
    (
        "_",
        "/Users/byron/dev/github.com/gitbutlerapp/gitbutler/target/debug/gitbutler-tauri",
    ),
    (
        "__CF_USER_TEXT_ENCODING",
        "0x1F5:0x0:0x0",
    ),
]

It looks like $SHELL can be used to figure out the login shell at least on MacOS. It's notable how many other additional variables are available, as if it was opened through a login shell already.

It really seems that a lot, but not all, of the login shell environment is picked up. It's unclear why

[vercel]

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[vercel]

@Byron is attempting to deploy a commit to the GitButler Team on Vercel.

A member of the Team first needs to authorize it.

[Byron]

I definitely changed more than originally planned, as I also added gix to read Git configuration. As it fully implements Git configuration, it will pick up more 'special' configuration that users might have to adjust their signing keys based on the repository at hand. git2 doesn't implement hasconfig.

Also note the config.trusted_program() calls which is gitoxides way of assuring no configuration of untrusted users (i.e. all others) is picked up to define which program to execute automatically.

[Byron]

This is how the hooks crate does it as well and it seems to work for hooks.

[Caleb-T-Owens]

@Byron Do we need to the same windows bash.exe lookup that the git2_hooks does?

[Caleb-T-Owens]

https://docs.rs/git2-hooks/latest/src/git2_hooks/hookspath.rs.html#179

[slamp]

I didn't see any basic stuff that seemed wrong or incorrect to me.

[Caleb-T-Owens]

There is a bail! macro which is equivalent to return Err(anyhow::anyhow!(...))

[Byron]

Good catch, done!