The condition here is the same used to apply a patch above that makes
this dependency necessary.
I'm not sure why this isn't needed on Darwin, but it's definitely
needed for building on Linux with pkgsLLVM or clangStdenv, and for
FreeBSD.
Normally I'd make the patch application unconditional to prevent
situations like this ending up unnoticed, but since it requires an
extra dependency and will be fixed in the next release anyway, let's
just leave it.
Without manual override following problematic code in generated
"configure" script (line 15918):
case "$host_os" in
# Guess yes on glibc systems.
*-gnu* | gnu*) gl_cv_func_signbit="guessing yes" ;;
# Guess yes on native Windows.
mingw*) gl_cv_func_signbit="guessing yes" ;;
# If we don't know, assume the worst.
*) gl_cv_func_signbit="guessing no" ;;
esac
results in declaration conflict with gnulib declaring
int signbit(double)
while system "math.h" providing modern declaration as
constexpr bool signbit(double)
Prior to this change, man pages from Nixpkgs written using the mdoc(7)
macros would start like this:
NC(1) BSD General Commands Manual NC(1)
and end like this:
BSD December 27, 2018 BSD
No matter what operating system they were run on.
It's far more accurate to say "Nixpkgs General Commands Manual", so
with this patch we configure groff to do just that. The variable is
called "operating-system", but I think it makes more sense to say
"Nixpkgs" than "NixOS" or something, because packages from Nixpkgs can
run on lots of operating systems, and the important thing is that the
package is from Nixpkgs.
These files are pure data, just fonts; they shouldn't have been moved
to the "perl" output, because the Perl programs (namely, gropdf) use
them from the main "out" output.
These files don't contain any references to more dependencies (Perl or
otherwise), so they don't bloat the closure. And the files themselves
are small; 276K total as of this commit.
This enables groff to correctly respond to the LESS_TERMCAP_*
environment variables, allowing colorized man pages.
Patch is taken from Arch Linux;
see https://bugs.archlinux.org/task/33760.
URLs to http://nix.cs.uu.nl/dist/tarballs. With content-addressable
mirror support (r9190, NIXPKGS-70) this is no longer necessary:
fetchurl will try to download from that location automatically. So
we can keep the original URLs.
svn path=/nixpkgs/trunk/; revision=9192
