In 3027bca, binutils was upgraded from 2.28.1 to 2.30. However, in 2.30,
the ldmain.c file within binutils, which the nixpkgs new-dtags.patch
file is meant to modify, was changed in such a way that the patch no
longer works. As a result, the new dtags are not actually enabled, and
binaries are built with RPATH set instead of RUNPATH, thereby preventing
LD_LIBRARY_PATH from overriding this built-in path. This change corrects
this. The patch file is no longer necessary because binutils's ldmain.c
now sets link_info.new_dtags based on the configuration flags.
This was probably not noticed immediately because, when the derivation
is built with nix-build, the fixupPhase runs patchelf --shrink-rpath.
patchelf converts any RPATH in the binary into RUNPATH (unless
--force-rpath is specified). Of course, if the binary is built without
nix-build (such as in a nix-shell), this never occurs, and any RPATH in
the binary is left in place.
`depsHostBuild` is not a thing, would never be a thing per the rules,
and isn't used anywhere. This is just my typo, hitherto unnoticed
because "host -> host" dependencies are by far the most obscure form.
HOST_PATH contains the path of the host package. This will include the
packages listed in buildInputs & depsHostHost. Use this to find
runtime commands that the host needs.
For instance to find the runtime version of perl,
$ PATH="$HOST_PATH" command -v perl
/nix/store/...-perl-5.28.0-aarch64-unknown-linux-android/bin/perl
This path should not be executed directly (it will break for cross
compilation). Only use it to find the location of executables that
will be run by your host system. Your build tools will, as always, be
available on the default PATH.
