Just now there is a dependency on cachix, which means we cannot test
the installer in CI if forks do not have the necessary secrets set up.
We replace this with a simple http server that serves the installer and
can be both used in CI and locally.
- This speeds up macOS builds from 30 minutes to 11 minutes (3x faster).
- Also improve error reporting e.g. printing out what actually failed to build.
- As a result we also no longer need swap.
As far as I can tell, there's no real reason either of these need to
be 664. I'm willing to bet they were just a typo that has lasted for
7 years. While this shouldn't change anything, this is, IMHO, more
correct, so let's stop perpetuating the wrong mode!
The Determinate Nix Installer has set nosuid and noatime in https://github.com/DeterminateSystems/nix-installer/pull/1338, and figured this perf and security improvement is worthy of upstreaming.
The /nix volume shouldn't have setuid binaries anyway, and filesystems seem to generally be noatime on macOS.
Further, the garbage collector doesn't use atime.
Was hoping to leave this enabled for a little while as core community
members test this script out, but Apple's aggressive release timeline
for macOS 15 Sequoia has caught us off-guard here.
It's probably not ideal for a general audience if the script spews all
of this output--and people can still force bash to run in trace mode
if we really need to debug a problem.
