Hopefully this fixes "unexpected EOF" failures on macOS
(#3137, #3605, #7242, #7702).
The problem appears to be that under some circumstances, macOS
discards the output written to the slave side of the
pseudoterminal. Hence the parent never sees the "sandbox initialized"
message from the child, even though it succeeded. The conditions are:
* The child finishes very quickly. That's why this bug is likely to
trigger in nix-env tests, since that uses a builtin builder. Adding
a short sleep before the child exits makes the problem go away.
* The parent has closed its duplicate of the slave file
descriptor. This shouldn't matter, since the child has a duplicate
as well, but it does. E.g. moving the close to the bottom of
startBuilder() makes the problem go away. However, that's not a
solution because it would make Nix hang if the child dies before
sending the "sandbox initialized" message.
* The system is under high load. E.g. "make installcheck -j16" makes
the issue pretty reproducible, while it's very rare under "make
installcheck -j1".
As a fix/workaround, we now open the pseudoterminal slave in the
child, rather than the parent. This removes the second condition
(i.e. the parent no longer needs to close the slave fd) and I haven't
been able to reproduce the "unexpected EOF" with this.
I saw this random failure in https://hydra.nixos.org/build/211811692:
error: opening /proc/15307/fd: No such process
while running nix-collect-garbage in a readfile-context.sh. This is
because we're not handling ESRCH errors reading /proc/<pid>/fd. So
just move the read inside the try/catch where we do handle it.
`nix copy` operations did not show progress. This is quite confusing.
Add a `progressSink` which displays the progress during `copyPaths`,
pretty much copied from `copyStorePath`.
Fixes https://github.com/NixOS/nix/issues/8000
This was causing random failures in tests/ca/substitute.ca: 'nix copy
--file ./content-addressed.nix' wouldn't get the default installable
'.' applied in InstallablesCommand::load(), so it would do nothing.
The curl download can outlive DrvOutputSubstitutionGoal (if some other
error occurs), so at shutdown setting the promise to an exception will
fail because 'this' is no longer valid in the callback. This can
manifest itself as a segfault, "corrupted double-linked list" or hang.
the term was hard to discover, as its definition and explanation were in
a very long document lacking an overview section.
search did not help because it occurs so often.
- clarify wording in the definition
- add an overview of installable types
- add "installable" to glossary
- link to definition from occurrences of the term
- be more precise about where store derivation outputs are processed
- installable Nix expressions must evaluate to a derivation
Co-authored-by: Adam Joseph <54836058+amjoseph-nixpkgs@users.noreply.github.com>
Presently when nix says something like:
```
these 486 paths will be fetched (511.54 MiB download, 6458.64 MiB unpacked):
...path1
...path2
...path3
...
...
...path486
```
It sorts path1, path2, path3, ..., path486 in lexicographic order of the
store path.
After this commit, nix will show path1, path2, path3, ..., path486 sorted by
StorePath name() (basically everything after the hash) rather than the store path.
This makes it easier to review what exactly is being downloaded at a glance,
especially when many paths need to be fetched.
We make sure the env var paths are actually set (ie. not "") before
sending them to the canonicalization function. If we forget to do so,
the user will end up facing a puzzled failed assertion internal error.
We issue a non-failing warning as a stop-gap measure. We could want to
revisit this to issue a detailed failing error message in the future.
Lazar Bodor
Yorick
Jonas Chevalier