For example, commands which extract a tarball should be cached (i.e
should use `runCommand` not `runCommandLocal`) because it allows builds
to download the unpacked result instead of having to write both to the
store
Write a `main.rs` to `src/bin/dummy` within the generated dummy source,
rather than `src/main.rs` to account for `illegalBin` test case
Signed-off-by: Roman Volosatovs <rvolosatovs@riseup.net>
* When checking the original source for its name, make sure we throw
away the string context so we don't end up actually depending on the
original source instead of the cleaned one
* mkDummySrc: also include `no_std` attrs for target_os = uefi
* buildDepsOnly: only check with `--all-targets` if doCheck enabled
* mkDummySrc: allow customizing dummy Rust file contents
* Instead of injecting our own dummy `build.rs` file, we will patch the
`Cargo.toml` files to specify a build script in the Nix store
* This allow cargo to notice the difference (i.e. changed build script
path) where it could not before (due to nix enforcing that all sources
always have the same timestamp)
* Seems like Nix can get unhappy if a path fragment is evaluated too
eagerly, giving errors like
`error: access to absolute path '/Cargo.toml' is forbidden in pure eval mode (use '--impure' to override)`
* Changing to using string manipulation seems to resolve the issue
* Rather than recursively look up all paths in a given project and then
filtering for cargo-specific files, we now use our own customized
traversal method to only capture the results we want.
* There are some edge cases where cargo will allow a lib.rs file to be
present but not a main.rs (e.g. a binary cannot be called "examples",
which will happen if the crate is called that and a main.rs file is
present)
