Last week I was hunting a production issue at work related to CppNix and
the only hint I had was this warning. While the cause was clearly a
CppNix issue since it was related to the libgit2-backed tarball cache,
the fact that this exception was hidden, made it way harder to discover
this. It would've saved me a lot of time[1] if the error was just
printed out (and thus would've ended up in the logs).
This is what this patch results in:
$ nix-instantiate -I https://notexisting.com --find-file . --option connect-timeout 1
warning: error: unable to download 'https://notexisting.com': Resolving timed out after 1001 milliseconds (curl error code=28); retrying in 265 ms
warning: error: unable to download 'https://notexisting.com/': Connection timed out after 1002 milliseconds (curl error code=28); retrying in 523 ms
warning: error: unable to download 'https://notexisting.com/': Connection timed out after 1001 milliseconds (curl error code=28); retrying in 1324 ms
warning: error: unable to download 'https://notexisting.com/': Connection timed out after 1000 milliseconds (curl error code=28); retrying in 2670 ms
warning:
… while downloading https://notexisting.com to satisfy NIX_PATH lookup (ignoring)
warning: unable to download 'https://notexisting.com/': Connection timed out after 1001 milliseconds (curl error code=28)
/path/to/nix/path/root
The `unable to download` part was hidden before. Granted, this is not the most
interesting showcase given the retries before, but I'd still argue that
this is useful for cases where you don't have a connection timeout (and
this was just the most trivial way to test for me).
[1] Unlucky as I was, I had to mount an older backup and nixos-enter
into the mount to reproduce this.
Change-Id: If2894369fc0b159a307b448e1ce7d9b54a327df6
Maximilian Bosch
079fe0ca50