This makes it possible to certain discern failures from empty
snippets, which I think is an ok review comment.
Maybe it should do so for swapped column indexes too, but I'm not
sure.
I don't think it matters in the grand scheme. We don't even have
a real use case for `nullopt` now anyway.
Since we don't have a use case, I'm not applying this logic to
higher level functions yet.
Unfortunately these don't render correctly, because they go into the
markdown renderer, instead of the terminal.
```
nix-repl> :doc lib.version
Attribute '[35;1mversion[0m'
… defined at [35;1m/home/user/h/nixpkgs/lib/default.nix:73:40[0m
```
We could switch that to go direct to the terminal, but then we should
do the same for the primops, to get a consistent look.
Reverting for now.
This reverts commit 3413e0338cbee1c7734d5cb614b5325e51815cde.
fetchurl can be given a name and url aside from just the url.
Giving a name can be useful if the url has invalid characters such as
tilde for the store.
... at call sites that are may be in the hot path.
I do not know how clever the compiler gets at these sites.
My primary concern is to not regress performance and I am confident
that this achieves it the easy way.
Known behavior changes:
- `MemorySourceAccessor`'s comparison operators no longer forget to
compare the `SourceAccessor` base class.
Progress on #10832
What remains for that issue is hopefully much easier!
- Fix eval cache not being persisted in `nix develop` (since #10570)
- Don't attempt to commit cache transaction if there is no active transaction, which will spew errors in edge cases
- Drive-by: trivial typo fix
Progress on #5638
There are still a global fetcher and eval settings, but they are pushed
down into `libnixcmd`, which is a lot less bad a place for this sort of
thing.
Continuing process pioneered in
52bfccf8d8.
This improves the error message of nix-env -qa, among others, which
is crucial for understanding some ofborg eval error reports, such as
https://gist.github.com/GrahamcOfBorg/89101ca9c2c855d288178f1d3c78efef
After this change, it will report the same trace, but also start with
```
error:
… while evaluating the attribute 'devShellTools'
… while evaluating the attribute 'nixos'
… while evaluating the attribute 'docker-tools-nix-shell'
… while evaluating the attribute 'aarch64-darwin'
… from call site
at /home/user/h/nixpkgs/outpaths.nix:48:6:
47| tweak = lib.mapAttrs
48| (name: val:
| ^
49| if name == "recurseForDerivations" then true
<same>
```
move together all syntactic and semantic information into one
page, and add a page on data types, which in turn links to the syntax and
semantics.
also split out the note on scoping rules into its own page.
Co-authored-by: Ryan Hendrickson <ryan.hendrickson@alum.mit.edu>
