Also begin to start work on cross compilation, though that will have to
be finished later.
The patches are based on the first version of
https://reviews.llvm.org/D99484. It's very annoying to do the
back-porting but the review has uncovered nothing super major so I'm
fine sticking with what I've got.
Beyond making the outputs work, I also strove to re-sync the packages,
as they have been drifting pointlessly apart for some time.
----
Other misc notes, highly incomplete
- lvm-config-native and llvm-config are put in `dev` because they are
tools just for build time.
- Clang no longer has an lld dep. That was introduced in
db29857eb3, but if clang needs help
finding lld when it is used we should just pass it flags / put in the
resource dir. Providing it at build time increases critical path
length for no good reason.
----
A note on `nativeCC`:
`stdenv` takes tools from the previous stage, so:
1. `pkgsBuildBuild`: `(?1, x, x)`
2. `pkgsBuildBuild.stdenv.cc`: `(?0, ?1, x)`
while:
1. `pkgsBuildBuild`: `(?1, x, x)`
2. `pkgsBuildBuild.targetPackages`: `(x, x, ?2)`
3. `pkgsBuildBuild.targetPackages.stdenv.cc`: `(?1, x, x)`
Use the same JDK for building bazel and for its runtime.
Effectively, the former `toolchain_hostjdk8` java toolchain has been deprecated
and should no longer be used (in newer bazel)[1]:
```
default_java_toolchain(
name = "toolchain_hostjdk8",
...
)
```
[1]: 4fc4868065/tools/jdk/BUILD.tools (L384-L387)
* use default stdenv (clang 7)
* add no-arc.patch to make the xcode_locate tool compile without libarc-lite
* remove the `-mmacosx-version-min=10.9` flag from the bootstrap compile script
Bazel 4 is going to be a long term support release.
Latest version in NixPkgs so far was 3.3.1
There's a need for more recent version
https://github.com/NixOS/nixpkgs/issues/97497
All versions from 3.5.0 to 3.7.1 had some reproducibility issues
as noted in issue above, but there also seems to be
a working PR for 3.7.1 now at
https://github.com/NixOS/nixpkgs/pull/105439
Notable changes from bazel_3 setup:
- put python to default bash path
For autodetecting python toolchain
with strict action_env on and without this change
bazel would fail to autodetect host python.
There are some repos that define hermetic python
toolchains, but they aren't easy to use yet. Also
telling python paths to bazel isn't a 1-liner it
seems:
- action_env=PATH would affect cache
- declaring toolchain via BUILD&WORKSPACE files
is not per-user but more like per-repo and
affects cache too
Using python from nixpkgs shouldn't be too bad
in the lack of simpler hermetic python toolchain
options
- bazel_4.updater is bazel on `bazel query` to support
new constructs in WORKSPACE (load of vars, transitive
load etc). This is more robust but requires bazel
to run the updater, using bazel_3 for now. This is
only needed to bump package version, doesn't introduce
bazel_4 build dependency on bazel_3
https://blog.bazel.build/2020/11/10/bazel-4.0-announce.htmlhttps://blog.bazel.build/2020/11/10/long-term-support-release.htmlhttps://github.com/bazelbuild/bazel/issues/12455https://github.com/bazelbuild/bazel/releases/tag/4.0.0https://blog.bazel.build/2021/01/19/bazel-4-0.html
