macOS: unexpected EOF reading a line

[roberth]

Describe the bug

Nix has failed to build on darwin with this log.
https://hydra.nixos.org/build/119296096/nixlog/1

It did succeed afterwards, so unless someone recognizes what's the problem in the log, it's ok to close this and move on.

The failure happens in test case tests/user-envs.sh, with the last couple of lines being:

    29 store paths deleted, 0.01 MiB freed
    + test -e /private/tmp/nix-build-nix-2.3.4.drv-0/nix-test/store/8fid272lbh1milx38cni6wi6dx7v8z7b-foo-1.0
    + '[' -e /private/tmp/nix-build-nix-2.3.4.drv-0/nix-test/store/kzm50sz0sp6gsvav10kx8xasppw0yrql-foo-2.0 ']'
    + nix-env -e '*'
    uninstalling 'foo-1.0'
    uninstalling 'bar-0.1'
    building '/private/tmp/nix-build-nix-2.3.4.drv-0/nix-test/store/prvd5da3s52k2gr2pvx510wvn7shyjqh-user-environment.drv'...
    created 0 symlinks in user environment
    ++ nix-env -q '*'
    ++ wc -l
    + test 0 -eq 0
    + nix-env -i foo
    installing 'foo-2.0'
    these derivations will be built:
      /private/tmp/nix-build-nix-2.3.4.drv-0/nix-test/store/wsrlj1hjzncx3g2i1jp65lbb1v3py2wp-foo-2.0.drv
    building '/private/tmp/nix-build-nix-2.3.4.drv-0/nix-test/store/wsrlj1hjzncx3g2i1jp65lbb1v3py2wp-foo-2.0.drv'...
    error: unexpected EOF reading a line

Steps To Reproduce

This may be a race condition or other intermittent bug.

The entire log of the build failure is available here:
https://hydra.nixos.org/build/119296096/nixlog/1

Expected behavior

Nix just builds on darwin without a test failure.

nix-env --version output

N/A

Additional context

[edolstra]

This test has been randomly failing for a while.

[domenkozar]

In case it's relevant, it also fails on bar:

    + nix-env -i bar-0.1
    installing 'bar-0.1'
    these derivations will be built:
      /private/tmp/nix-build-nix-2.3.6.drv-0/nix-test/store/qk9gcc2say7156yhmdzdiwrybm5gyi0s-bar-0.1.drv
    building '/private/tmp/nix-build-nix-2.3.6.drv-0/nix-test/store/qk9gcc2say7156yhmdzdiwrybm5gyi0s-bar-0.1.drv'...
    error: unexpected EOF reading a line

[domenkozar]

#3137 looks quite relevant, there might be a bug in Nix.

[domenkozar]

Possibly relevant: #1704

[abathur]

I'm not sure it's the same issue since the context is different, but I've run into some flaky instances of this message. Let me know if you think I should open this separately?

I took a little time this week to pick at writing a plain bash script to set up Nix on travis-CI in a way that is hopefully more maintainable than the Ruby language integration, but as soon as I had the install working correctly I started noticing flaky failures with this message:

installing 'nix-2.3.7'
error: unexpected EOF reading a line

---- oh no! --------------------------------------------------------------------

Some notes:

• It doesn't always fail
• It's not always the same job that fails
• I have yet to observe the linux build fail.
• I have yet to observe the macOS 10.13 build fail (I have seen every macOS config 10.14+ fail at least once).

Edit: I've force a rebuild on 10.13 every time I can remember for the past 5 days and I've finally strung together about 60 builds without a single 10.13 failure. Given how common the 10.14 and 10.15 failures have been, I'm feeling fairly confident at this point that (again, assuming this is the same as the issue observed here) that this issue doesn't manifest on 10.13.

I haven't quite decided yet if I should still see it as a blocker for my purpose or not 😬

Here are links to specific runs:

• 4 runs that each had a single (generally different) job fail: 16, 17, 18, 22
• 2 that ran all clean: 19, 20

[abathur]

I saw a fresh probable instance of this on CI today:

installing 'nix-2.3.7'

building '/nix/store/hqqr5jaxy2kaxij5jzz3kd8gd63qfdkm-user-environment.drv'...

created 7 symlinks in user environment

installing 'nss-cacert-3.49.2'

building '/nix/store/055gdwqrwg839skhjcp65r2inyzdxs1p-user-environment.drv'...

created 9 symlinks in user environment

unpacking channels...

error: unexpected EOF reading a line

error: program '/nix/store/5ira7xgs92inqz1x8l0n1wci4r79hnd0-nix-2.3.7/bin/nix-env' failed with exit code 1

�[32mAlright! We're done!

�[0m

But fetching the nixpkgs channel failed. (Are you offline?)

To try again later, run "sudo -i nix-channel --update nixpkgs".



Before Nix will work in your existing shells, you'll need to close

them and open them again. Other than that, you should be ready to go.

[abathur]

I asked @domenkozar about this on IRC and he confirmed that he has not seen this on github-actions macOS runners running either 10.14 or 10.15.

[abathur]

I have been running Nix builds on a 2013 MBA running macOS 10.14 as I poke at Big Sur installer updates, and I've been seeing spotty EOF errors (on the scale of 0-4 per distinct attempt to build). Most of them have been in tests/user-envs.sh, but I've also seen tests/remote-store.sh come up at least once.

Edit: It seems like these have been growing more common as I kept building. I've attached a log of a loop I did where it tried and failed more than 10 times. At some point it got stuck, so I killed it. After a reboot it built fine.