My builds are still failing. This time with...
```
error: getting status of /home/wpcarro/nixpkgs-channels: Permission denied
```
...what confused me was the following:
```shell
$ sudo -u buildkite-agent-socrates stat /home/wpcarro/nixpkgs-channels
permission denied
```
But `ls -al /home/wpcarro | grep nixpkgs-channels` showed `r-w` for all users...
Thankfully @riking on ##tvl told me that I should check the permissions for
/home/wpcarro and /home...
After running `ls -al /home`, I saw `---` for all user... I then reproduced the
error by running:
```shell
$ sudo -u buildkite-agent-socrates stat /home
permission denied
```
Great!
So then I moved nixpkgs-channels to /var/lib/buildkite-agent-socrates. @edef
recommended that I read more about DynamicUser= setting for systemd, which looks
relevant after I took a cursory glance.
I'll also want a more declarative way to manager this, but I'm making small
improvements every day.
For now, I'm supporting two CI pipelines:
- build-socrates
- build-briefcase
Conceptually, build-briefcase should cover what build-socrates does now, but
eventually I would like build-socrates to call `switch-to-configuration` so that
all of my websites, etc. stay fresh.
Unforeseen problem: `buildkite-agent` runs its builds in a separate directory,
so if I want the `nix-build` command to build the newly checked out code, I need
to set <briefcase> to the CWD.
I've encountered a few problems with attempting to support nixos-rebuild:
- the activation step requires `sudo` privileges
- the `buildkite-agent` runs on the same machine, socrates, that is rebuilding
itself. This means that when the activation step runs, it will attempt to
restart `buildkite-agent` when the agent is still working
I'm slowly removing places in my nix code that rely on '<bracket>' notation, so
that I no longer depend on NIX_PATH being set. I still have more work to do.
{covid-uk,sandbox}/default.nix are breaking when I attempt to run my
build-socrates.sh script locally, so I'm temporarily disabling them until I can
get CI working as I expect.
- using `set -euo pipefail` for setting recommended failure-modes
- using `set -x` and `echo "$PATH"` to debug my failing build
Sidenote: I find BuildKite's documentation quite helpful!
