the foldl is equivalent to a zip with concat. list concatenation in nix
is an O(n) operation, which makes this operation extremely inefficient
when large numbers of modules are involved.
this change reduces the number of list elements by 7 million on the
system used to write this, total memory spent on lists by 58MB, and
total memory allocated on the GC heap by almost 100MB (with a similar
reduction in GC heap size). it's also slightly faster.
While it is a fact of life that aarch64-darwin is built on Hydra, it has
never formally been elevated from the Tier 7 state it was originally
assigned in RFC 0046. Since platform Tier status is not only
descriptive, but also normative, a consensus to commit to supporting
aarch64-darwin would need to be reached.
`builtins.currentSystem` is not available in pure eval. For this
particular test, we don't really care since it's all about generating
.drv files.
Fixes the following error:
$ nix flake check
warning: unknown flake output 'lib'
error: attribute 'currentSystem' missing
at /nix/store/8wvnlbjxlr90kq2qa6d9zjpj8rqkilr5-source/lib/tests/misc.nix:499:73:
498| let
499| deriv = derivation { name = "test"; builder = "/bin/sh"; system = builtins.currentSystem; };
| ^
500| in {
(use '--show-trace' to show detailed location informat
Move function spdxLicense, internally used in yarn2nix
to lib/meta.nix, and
rename to getLicenseFromSpdxId
A similar function is implemented in poetry2nix,
but the one originally in yarn2nix seems beter.
since it falls back to an license-like attrset
for mismatched case
instead of a plain string
Makes any programming errors more likely to show up early.
Non-obvious changes because of this:
- Ignore the `evalConfig` result in `reportFailure`; we're not checking
it at that point.
- Pre-increment `$fail` and `$pass` to make sure the arithmetic doesn't
result in a zero, which would result in a non-zero exit code for the
expression.
mkDerivedConfig : Option a -> (a -> Definition b) -> Definition b
Create config definitions with the same priority as the definition of another option.
This should be used for option definitions where one option sets the value of another as a convenience.
For instance a config file could be set with a `text` or `source` option, where text translates to a `source`
value using `mkDerivedConfig options.text (pkgs.writeText "filename.conf")`.
It takes care of setting the right priority using `mkOverride`.
recursiveUpdate does not produce an attrset until it has evaluated
both its arguments to weak head normal form.
nix-repl> lib.recursiveUpdate (throw "a") (throw "b")
error: b
nix-repl> lib.recursiveUpdate (throw "a") {}
error: a
The current implementation of `mutuallyExclusive` builds a new list with
length subtracted by one on every recursive call which is expensive. When
b is empty, the function still traverses a in its entirety before returning
a result.
The new implementation uses `any` to check if each element of list b is in
list a using `elem`. This maintains short circuiting when list a or b is empty
and has a worst case time complexity of O(nm).
the fix to extendDerivation in #140051 unwittingly worsened eval performance by
quite a bit. set elements alone needed over 1GB extra after the change, which
seems disproportionate to how small it was. if we flip the logic used to
determine which outputs to install around and keep a "this one exactly" flag in
the specific outputs instead of a "all of them" in the root we can avoid most
of that cost.
