The git fetcher code used to dereference the (potentially empty) `ref`
input attribute. This was magically working, probably because the
compiler somehow outsmarted us, but is now blowing up with newer nixpkgs
versions.
Fix that by not trying to access this field while we don't know for sure
that it has been defined.
Fix#6554
Without the change llvm build fails on this week's gcc-13 snapshot as:
src/libutil/json.cc: In function 'void nix::toJSON(std::ostream&, const char*, const char*)':
src/libutil/json.cc:33:22: error: 'uint16_t' was not declared in this scope
33 | put(hex[(uint16_t(*i) >> 12) & 0xf]);
| ^~~~~~~~
src/libutil/json.cc:5:1: note: 'uint16_t' is defined in header '<cstdint>'; did you forget to '#include <cstdint>'?
4 | #include <cstring>
+++ |+#include <cstdint>
5 |
This solves the error
error: cannot connect to socket at '/nix/var/nix/daemon-socket/socket': Connection refused
on build farm systems that are loaded but operating normally.
I've seen this happen on an M1 mac running a loaded hercules-ci-agent.
Hercules CI uses multiple worker processes, which may connect to
the Nix daemon around the same time. It's not unthinkable that
the Nix daemon listening process isn't scheduled until after 6
workers try to connect, especially on a system under load with
many workers.
Is the increase safe?
The number is the number of connections that the kernel will buffer
while the listening process hasn't `accept`-ed them yet.
It did not - and will not - restrict the total number of daemon
forks that a client can create.
History
The number 5 has remained unchanged since the introduction in
nix-worker with 0130ef88ea in 2006.
Add a new `file` fetcher type, which will fetch a plain file over
http(s), or from the local file.
Because plain `http(s)://` or `file://` urls can already correspond to
`tarball` inputs (if the path ends-up with a know archive extension),
the URL parsing logic is a bit convuluted in that:
- {http,https,file}:// urls will be interpreted as either a tarball or a
file input, depending on the extensions of the path part (so
`https://foo.com/bar` will be a `file` input and
`https://foo.com/bar.tar.gz` as a `tarball` input)
- `file+{something}://` urls will be interpreted as `file` urls (with
the `file+` part removed)
- `tarball+{something}://` urls will be interpreted as `tarball` urls (with
the `tarball+` part removed)
Fix#3785
Co-Authored-By: Tony Olagbaiye <me@fron.io>
Robert Hensing
Maximilian Bosch