tests/wrapper-roles.nix
The Fil-C compiler and bintools wrappers must not share a role salt with the native ones. When they did, both wrappers accepted both roles' flags: a native zlib in nativeBuildInputs came first in Fil-C links (undefined pizlonated_deflate), and Fil-C's zlib reached native links.
λpkgsFilc
pkgsFilc.callPackage
λstdenv, buildPackages, zlib
stdenv.mkDerivation
Spliced: the build platform's zlib here, Fil-C's in buildInputs.
[ "${stdenv.cc.suffixSalt}" != "${buildPackages.stdenv.cc.suffixSalt}" ]
cat > z.c <<'C'
#include <stdio.h>
#include <zlib.h>
int main(void) {
unsigned char out[64];
unsigned long len = sizeof out;
if (compress(out, &len, (const unsigned char *)"hello", 5) != Z_OK)
return 1;
printf("%s %lu\n", zlibVersion(), len);
return 0;
}
C
$CC z.c -lz -o z-filc
./z-filc
$CC_FOR_BUILD z.c -lz -o z-native
./z-native
# Each program must load its own platform's zlib.
readelf -d z-filc | grep -q 'libc.so.6666'
! readelf -d z-native | grep -q 'libc.so.6666'
touch "$out"
{ }