Under RVM some users have reported that running git-up works fine, but
running git up results in one of many issues, the most common being:
spawn.rb:187:in `_pspawn': Invalid command name (ArgumentError)
The underlying cause is a combination of the way RVM sets the correct
ruby interpreter in the environment, and the way git interprets and
executes git up.
When you run git [some command] git will first look internally to see
if it can fulfil the command, then it will attempt to "shell out" and run
whatever git-[some command] executable it can find in your $PATH.
When git "shells out" all of the environmental variables will be
exposed, and it will be able to find our git-up executable in the $PATH.
However because of the way RVM magically sets your ruby interpreter,
when git-up is ran ruby still points to the non-RVM system default.
To fix this we need to make sure that RVM gets to do it's business
before git-up is ran.
RVM provides a handy way of doing this called "wrappers", so let's generate a wrapper for git-up like so:
rvm wrapper [ruby-version]@[gemset-name] --no-prefix git-up
Next we need to make sure that git finds our wrapper first, to do this
we can make use of the /usr/libexec/git-core directory that git uses
for some of it's own commands.
sudo ln -s $HOME/.rvm/bin/git-up /usr/libexec/git-core/git-up
Finally we need to modify our wrapper to prevent bundler issues when we are working on ruby projects, so open that file in your favourite editor, find this line:
exec git-up "$@"
and change it to:
ruby `which git-up` "$@"
This may seem strange, but it bypasses ruby_noexec_wrapper which
may cause issues if you are working in a project with a Gemfile.