Closes#16182
This improves the error message
Error: _assignFirst found no valid variant!
which occurred when the set of outputs was not sufficient to set
the various outputDev, outputBin, etc variables. Specifically, this
would mean that "out" is not among the outputs, which is valid for
a derivation.
This changes the message to something like
error: _assignFirst: could not find a non-empty variable to assign to outputDev. The following variables were all unset or empty: dev out.
If you did not define an "out" output, make sure to define all the specific required outputs: define an output for one of the unset variables.
While this isn't a full explanation of what stdenv can and can not do,
I think it's vast improvement over the 0 bits of information that it
used to provide. This at least gives a clue as to what's going on, and
even suggests a fix, although probably multiple such fixes are required
in an instance where someone starts with a no-out derivation from scratch
(and decide to persist).
This restarts a Haskell section in the nixpkgs manual. The content
presented here has been written from scratch, although some parts of it
take inspiration from the existing haskell4nix documentation.
It is by no means complete, the idea is mostly to get the ball rolling
in some way. Upcoming tasks are hinted at in the comments in the
documentation file.
matching on only `{...}` does not trigger if the role tag is preceded by
something usually considered a semantic separator that isn't a separator
as markdown knows it, e.g. punctuation characters.
The thunderbird derivation is using `buildMozillaMach` these days,
shared with Firefox and Librefox, so it is probably the correct
, although more complicated, successor.
This is preferable because it prevents things like disk corruption (requiring the user to delete the disk image when starting up) that I consistently ran into.
Move the manpage-to-URL mapping to `doc/manpage-urls.json` so that we can
reuse that file elsewhere, and generate the `link-manpages.lua` filter from
that file.
Also modify the Pandoc filter so that it doesn't wrap manpages that are
already inside a link.
Keeping a Lua filter is essential for speed: a Python filter would
increase the runtime `md-to-db.sh` from ~20s to ~30s (but Python is not
to blame; marshalling Pandoc types to and from JSON is a costly operation).
Parsing in Lua seems tedious, so I went with the Nix way.
The new derivation should evaluate only if the old derivation does.
Sadly this means that the old derivation cannot depend on the new one
any more, which was used by xorgserver on Darwin. But this is not a
problem as `overrideAttrs` can (and should) usually be used instead.
This change allowed catching an invalid `meta.platforms` in the linux_rpi
kernels, which use `overrideDerivation`.
The trailing `'` was included by mistake and is not supposed
to be there:
```ShellSession
$ base64 -w0 /etc/ssh/ssh_host_ed25519_key.pub
c3NoLWVkMjU1MTkgQUFBQUMzTnphQzFsWkRJMU5URTVBQUFBSUpCV2N4Yi9CbGFxdDFhdU90RStGOFFVV3JVb3RpQzVxQkorVXVFV2RWQ2Igcm9vdEBuaXhvcwo=
```
The reason it did not cause issues before is because
Nix ignores everything after the `=`:
3dbf9b5af5/src/libutil/util.cc (L1539-L1540)
… so it's harmless but still worth fixing.
- Extensive documentation in NixOS manual
- Deterministic mode that fixes various identifiers relative to disk
partitions and filesystems in ext4 case
- UEFI variable recording
