I am closing down my old blog on socketwiz.com and I didn't have much content over there and this was and article I felt like preserving.
First off the problem. I like to develop on
smartos because it is based on Solaris and has
all of the conveniences of Linux with a few extras namely zfs, zones
and dtrace. It’s dtrace that I’m going to discuss today. I run a
very specialized version of vim. By specialized I mean I have a bunch
of
addons. In
particular, YouCompleteMe
and UltiSnips requires
that vim be a particular version and have python support compiled
in. The vim for smartos unfortunately does not so I build
my own. This leads us to my problem. I also use git and when I do
commits I want it to use vim, specifically my custom vim, otherwise it
throws an error on startup complaining about the lack of python
support.
YouCompleteMe unavailable: requires Vim 7.3.584+
UltiSnips requires py >= 2.6 or any py3
Press ENTER or type command to continue
To fix this there are two options:
- git config –global core.editor "/path/to/vim"
- set the GIT_EDITOR, VISUAL, or EDITOR environment variables.
I opted for the later because I share my $HOME/.gitconfig on 3
different systems, smartos, mac, and windows, and vim lives in
different locations on each of them. The environment variable would be
the ideal solution but it seems to be ignored because I have EDITOR
set already. I tried setting GIT_EDITOR to no avail. So what’s going
on and more importantly how can I fix it? One option might be to
download the source code for git and try to debug it and figure out
what the problem is, but that seems like a lot of work for such a
small annoyance. I chose to utilize dtrace, after all theres no since
running on smartos if you’re not going to take advantage of its
conveniences. My goal was to try and figure out where git was
searching for vim in an attempt to try and figure out why it was not
finding my vim, and instead using the system vim. My path has my vim
ahead of the system vim so in theory it should have found it. Here is
the command I came up with:
$ dtrace -n 'syscall::exec*:entry /execname=="git"/ { printf("%s\n", copyinstr(arg0)); }'
I fired up tmux because I run smartos remotely and I wanted to take
advantage of the multiple windows so I didn’t have to make 2 ssh
connections. In the first window I ran sudo -i because dtrace wants to
run as root, then I ran the command above. In the second window I ran
git commit and here is what dtrace output:
dtrace: description 'syscall::exec*:entry ' matched 1 probe
CPU ID FUNCTION:NAME
3 7129 exece:entry /opt/local/libexec/git-core/vi
3 7129 exece:entry /opt/local/bin/vi
3 7129 exece:entry /opt/local/bin/vi
3 7129 exece:entry /usr/local/sbin/vi
3 7129 exece:entry /usr/local/bin/vi
3 7129 exece:entry /opt/local/sbin/vi
3 7129 exece:entry /opt/local/bin/vi
3 7129 exece:entry /usr/sbin/vi
3 7129 exece:entry /usr/bin/vi
Aha! I don’t understand why, but for some reason it’s not looking for
vim at all, it’s looking for vi. I could fix this in one of two
ways. Download the source for git and try and figure out why it’s
doing this, or simply make a symbolic link from vi to my vim and
call it a day. I chose the latter:
sudo ln -s /opt/local/bin/vim /opt/local/bin/vi
Now when I run “git commit” I get:
dtrace: description 'syscall::exec*:entry ' matched 1 probe
CPU ID FUNCTION:NAME
1 7129 exece:entry /opt/local/libexec/git-core/vi
1 7129 exece:entry /opt/local/bin/vi
Categories: #technology