need to update binary path in .plist after upgrade

[gperciva]

Looks like the .plist hard-codes the version-specific path, i.e.

/usr/local/Cellar/tarsnap-gui/1.0/Tarsnap.app/Contents/MacOS/Tarsnap

We'll need to update this when there's a new version, or (probably better) make sure that we get the symlink to that file rather than the path itself. (I assume that brew sets up something like /usr/local/bin/tarsnap -> /usr/local/Cellar/tarsnap-gui/1.0/Tarsnap.app/Contents/MacOS/Tarsnap )

Thread here:
http://mail.tarsnap.com/tarsnap-users/msg01457.html
http://mail.tarsnap.com/tarsnap-users/msg01464.html

[gperciva]

This is being addressed in #196 (that PR still needs to add launchd unload ... && launchd load ...).

[DomT4]

or (probably better) make sure that we get the symlink to that file rather than the path itself.

If you use the opt prefix it won't break across upgrades, and indeed, will keep working if people unlink tarsnap-gui from HOMEBREW_PREFIX for whatever reason. Opt prefix is HOMEBREW_PREFIX/opt/tarsnap-gui, with HOMEBREW_PREFIX usually being /usr/local.

FWIW, as long as the formula is installed, brew --prefix <xyz> will always return the unversioned symlink rather than the versioned path.

[shawwn]

The cask formula mentioned here uses the binary stanza of the cask formula to ensure tarsnap-gui is in the user's PATH.

The takeaway is that the plist file can just hardcode /usr/local/bin/tarsnap-gui.