Most of the eval cache logic is flake-independent and libexpr,
but the loading part is not.
`nix-flake` is the right component for this, as the eval cache
isn't exactly specific to the command line.
we have now merge queues for maintainance branches. We still build it
for master to have our installer beeing updated. In future this part
could go in new workflow instead.
This barfed with
error: [json.exception.type_error.302] type must be string, but is array
on `nix build github:malt3/bazel-env#bazel-env` because it has a `exportReferencesGraph` with a value like `["string",...["string"]]`.
Add a `UsernameAuth` struct and optional `usernameAuth` field to
`FileTransferRequest` to support programmatic username/password
authentication.
This uses curl's `CURLOPT_USERNAME`/`CURLOPT_PASSWORD` options, which
works with multiple protocols (HTTP, FTP, etc.) and is not specific to
any particular authentication scheme.
The primary motivation is to enable S3 authentication refactoring where
AWS credentials (access key ID and secret access key) can be passed
through this general-purpose mechanism, reducing the amount of
S3-specific code behind `#if NIX_WITH_CURL_S3` guards.
This breaks gdb pretty-printers inserted into .debug_gdb_scripts section,
because it implies --compress-debug-sections=zlib, -Wa,--compress-debug-sections.
This is very unfortunate, because then gdb can't use pretty printers for
Boost.Unordered (which are very useful, since boost::unoredred_flat_map is
impossible to debug). This seems perfectly fine to disable in the dev-shell for
the time being.
See [1-3] for further references.
With this change I'm able to use boost's pretty-printers out-of-the box:
```
p *importResolutionCache
$2 = boost::concurrent_flat_map with 1 elements = {[{accessor = {p = std::shared_ptr<nix::SourceAccessor> (use count 5, weak count 1) = {
get() = 0x555555d830a8}}, path = {static root = {static root = <same as static member of an already seen type>, path = "/"},
path = "/derivation-internal.nix"}}] = {accessor = {p = std::shared_ptr<nix::SourceAccessor> (use count 5, weak count 1) = {
get() = 0x555555d830a8}}, path = {static root = {static root = <same as static member of an already seen type>, path = "/"},
path = "/derivation-internal.nix"}}}
```
When combined with a simple `add-auto-load-safe-path ~/code` in .gdbinit
[1]: https://gerrit.lix.systems/c/lix/+/3880
[2]: https://git.lix.systems/lix-project/lix/issues/1003
[3]: https://sourceware.org/pipermail/gdb-patches/2025-October/221398.html
