This is to simplify remote build configuration. These environment
variables predate nix.conf.
The build hook now has a sensible default (namely build-remote).
The current load is kept in the Nix state directory now.
Once upon a time, I wrote my bachelors thesis about functional
deployment mechanisms.
I had to evaluate several szenarios where package management and
deployment were relevant. One szenario was to do distributed builds
over several machines.
I told myself: Weee, nix can do this! And with nix, this is actually
save, as you do not have side effects when building!
So I started. I use a cloud to set up four virtual machines where I
wanted to do the build. A fifth machine was used as master to distribute
the builds. All was good.
I created the necessary SSH keys, made sure every machine was reachable
by the master and configured the build in my remotes.conf.
When I started to try to build weechat from source, the build failed. It
failed, telling me
error: unable to start any build; either increase ‘--max-jobs’ or enable distributed builds
And I started to dig around. I digged long and good. But I wasn't able
to find the issue.
I double and triple checked my environment variables, my settings, the
SSH key and everything.
I reached out to fellow Nixers by asking on the nixos IRC channel. And I
got help. But we weren't able to find the issue, either.
So I became frustrated. I re-did all the environment variables.
And suddenly,... it worked! What did I change? Well... I made the
environment variables which contained pathes contain absolute pathes
rather than relatives.
And because I like to share my knowledge, this should be put into the
documentation, so others do not bang their heads against the wall
because something is not documented somewhere.
