This commit adds the CentOS 7.4 base image from the CentOS mirror, for use with
building RPMs or evaluating Nix expressions in a CentOS image.
When CentOS 7.5 comes out, I will swap this URL to the permanently vaulted image.
On non-GNU (gcc) compilers, there is no "/lib/gcc/..."
so when this is eventually expanded this is empty
resulting in an incomplete "-idirafter " that
eats the next argument:
-idirafter -B/nix/store/wamjwwdvkmhbf4f2902nhw8jxxzv0hy3-clang-wrapper-4.0.1/bin/
Certain tools, e.g. compilers, are customarily prefixed with the name of
their target platform so that multiple builds can be used at once
without clobbering each other on the PATH. I was using identifiers named
`prefix` for this purpose, but that conflicts with the standard use of
`prefix` to mean the directory where something is installed. To avoid
conflict and confusion, I renamed those to `targetPrefix`.
This continues #23374, which always kept around both attributes, by
always including both propagated files: `propgated-native-build-inputs`
and `propagated-build-inputs`. `nativePkgs` and `crossPkgs` are still
defined as before, however, so this change should only barely
observable.
This is an incremental step to fully keeping the dependencies separate
in all cases.
After #31497 starter quoting all values, there arouse the need to left some
values evaluated.
`--set-default var value` expands to `export var=${var-value}`, where value is
not evaluated and literally assigned to var unless it is already set.
`--set-eval var value` expands to `export var=$(eval echo value)`, where value
is evaluated by `eval`.
Currently we wrap ssh so it can find the config file passed in by
<ssh-config-file>. If one however uses ProxyCommand ssh, then ssh that
is on PATH is taken (which is also unavailable when using nix-shell
--pure), which is the plain ${openssh}/bin/ssh.
This commit makes sure our wrapped ssh is available on PATH.
For a while now, the only thing the 'uboot' attribute does is to tell
whether to add ubootTools to kernel/initrd builds. That can be
determined with platform.kernelTarget == "uImage" just as well.
If a dynamic linker for target is not found the generated script fails
due to unbound variable error (due to "set -u"). Correct by specifying
default value with dynamicLinker:- and not generating ldflagsBefore if
no linker is found.
This problem was found when cross compiling to mingw32 targets
The previous one was very bad and worsened the situation.
But even running with some nix-1.12 I'm unable to reproduce
the original failure. Let's unblock channels for now.