This commit solves an issue where the environment handed to
`/usr/sbin/installer` is not the same as the environment used by the
graphical PKG installer.
This is evident in some post-install scripts, e. g. the
`component-10.pkg/Scripts/postinstall` script in the `dymo-label`
cask. The code says:
```
USER_ID=`id -u ${USER}`
launchctl bootstrap gui/$USER_ID /Library/LaunchAgents/com.dymo.dls.webservice.plist
```
The graphical installer will export e. g. `USER=alice`, and
everything works as intended.
However, `brew cask install` does not override `sudo`’s default,
which is `USER=ROOT`. This violates the assumptions in the script.
This commit fixes the issue by configuring `sudo` to override the
following environment variables with the proper user name:
- `LOGNAME`
- `USER`
- `USERNAME`
`brew cask list` supports the `--full-name` flag which will include the tap
name for casks not part of the core caskroom/cask tap. For example, if
cask "foo-beta" is installed from the caskroom/versions cask, `brew cask
list --full-name` will report the name as "caskroom/versions/foo-beta".
Don't add these unconditionally or with Bundler to speed things up a
bit. Also, to speed things up further cache these arguments so we don't
have to do the same generation every time.
The `brew test` tests were failing as they were unable to include
`test/unit/assertions`. This is because it's a gem and we were setting
the `GEM_HOME` so system gems were being ignored.
While I was there and examining the `$LOAD_PATH`: reduce the number of
things we add there by using `Bundler.with_clean_env` and only adding
`HOMEBREW_LIBRARY_PATH` in the `$LOAD_PATH` if it isn't already there
(which it always is [and has to be] for integration tests).
This also seems to have the side effect of speeding up integration
tests from 1m26s to 1m8s on my machine.
