* writers.makeScriptWriter: fix on Darwin\MacOS
On Darwin a script cannot be used as an interpreter in a shebang line, which
causes scripts produced with makeScriptWriter (and its derivatives) to fail at
run time if the used interpreter was wrapped with makeWrapper (as in the case
of python3.withPackages).
This commit fixes the problem by detecting if the interpreter is a script
and prepending its shebang to the final interpreter line.
For example if used interpreter is;
```
/nix/store/ynwv137n2650qy39swcflxbcygk5jwv1-python3-3.8.3-env/bin/python
```
which is a script with following shebang:
```
#! /nix/store/knd85yc7iwli8344ghav3zli8d9gril0-bash-4.4-p23/bin/bash -e
```
then the shebang line in the produced script will be
```
#! /nix/store/knd85yc7iwli8344ghav3zli8d9gril0-bash-4.4-p23/bin/bash -e /nix/store/ynwv137n2650qy39swcflxbcygk5jwv1-python3-3.8.3-env/bin/python
```
This works on Darwin since there does not seem to be a limit to the length
of the shabang line and the shebang lines support multiple arguments to
the interpreters (as opposed to linux where the kernel imposes a strict limit
on shebang lengh and everything following the interpreter is passed to it
as a single string).
fixes; #93609
related to: #65351#11133 (and probably a bunch of others)
NOTE: scripts produced on platforms other than Darwin will remain unmodified
by this PR. However it might worth considering extending this fix to BSD systems
in general. I didn't do it since I have no way of testing it on systems other
than MacOS and linux.
* writers.makeScriptWriter: fix typo in comment
* writers.makeScriptWriter: fail build if interpreter of interpreter is a script
"bazel fetch" will, by default, fetch everything that _might_ be used,
including things that will later be discarded due to the way the build
is configured.
Concretely, this means that for some builds of Java packages, this will
avoid failures where the builder tries to retrieve the JDK from /usr/share/java
(or equivalent).
This also means that for most packages we can fetch _fewer_ dependencies,
since the standard tree pruning for artifacts to fetch will take effect.
fetchConfigured is disabled by default since it changes the fetch hashes
of tensorflow/tensorflow2 (since it ends up fetching less).
The image tag can be specified or generated from the output hash.
Previously, a generated tag could be recovered from the evaluated
image with some string operations.
However, with the introduction of streamLayeredImage, it's not
feasible to compute the generated tag yourself.
With this change, the imageTag attribute is set unconditionally,
for the buildImage, buildLayeredImage, streamLayeredImage functions.
When features were supplied in cargoBuildFlags, the binaries were built
with these features enabled. Unless checking was disabled, `cargo test`
was executed without these build flags, meaning the binaries were
rebuilt and overwritten without the specified features.
Fix this bug by running tests after the installation phase.
This is supposed to shareDocName to a fallback value if it can't be
determined from looking at the configure script. But the conditional
checked whether shareDocName was set, rather than if it wasn't. This
meant that if shareDocName had been detected from a configure script,
it would be immediately overridden by the package name, and if it
couldn't be detected, shareDocName would remain unset.
This resulted in QEMU installing files like $out/share/doc/index.html,
which should of course have been in $out/share/doc/qemu/index.html.
An interesting side effect of this is that, since
9f8751528cd89d343258dd718afa56f8590917bb when this code was added, the
detected package name has never actually been used for installing
documentation, because it would always be overridden. So this patch
will actually enable that for the first time, four years later.
Fixes: https://github.com/NixOS/nixpkgs/issues/90486
Cargo sets `CARGO_FEATURE_*` for all features when running a build
script:
https://doc.rust-lang.org/cargo/reference/environment-variables.html#environment-variables-cargo-sets-for-build-scripts
Some crates have build scripts (e.g. openblas-src) that rely on the
feature variables being properly set.
Since we now need several representations of features, this change
also updates `createFeatures` to be a list of features, rather than
`rustc` feature arguments. `configureCrate` and `buildCrate` then
build the required representations as-needed.
Fixes#68978
