Dwarf Fortress expression should set dontPatchELF = true

[michalrus]

Issue description

If you look at

nixpkgs/pkgs/games/dwarf-fortress/game.nix

Lines 31 to 34 in 224c24f

	patchelf \
	--set-interpreter $(cat ${stdenv.cc}/nix-support/dynamic-linker) \
	--set-rpath "${libpath}" \
	$out/libs/Dwarf_Fortress

— it’s using patchelf, and not settingdontPatchELF = true.

Most probably it should do that, as suggested by @ttuegel on freenode/#nixos:

• 22:10 michalrus: Oh! You probably need to set `dontPatchELF = true;' in your derivation. If that doesn't work, report it over at https://github.com/nixos/patchelf.
• 22:13 Dwarf Fortress uses patchelf manually and they don’t use dontPatchELF, see https://github.com/NixOS/nixpkgs/blob/master/pkgs/games/dwarf-fortress/game.nix
• 22:16 michalrus: They really should... I guess they just get lucky that the automated patchelf call doesn't break anything.

[joachifm]

Is there an actual problem? The patchelf setup hook removes entries in the rpath that appear redundant, so it's not clear to me that it inherently conflicts with setting the rpath manually (though it's obvious that it can).

[ttuegel]

This is not an actual problem, but something that could become a problem in the future. By the way, for pre-built binaries, you probably also always want dontStrip = true;.

[abbradar]

Hm, why can it be a problem? I usually leave it (setting dontStrip = true meanwhile) to clean unused RPATH entries.

[ttuegel]

Hm, why can it be a problem?

I've had problems in the past when I am appending to the RPATH and the pre-built binary has RPATH entries which are not "needed," but used to dlopen things at runtime, but if you are just doing --set-rpath anyway, I suppose it is fine.

[abbradar]

Ah! Yes, this can be a problem, but I've used --add-needed to fix this more granularly... unless I'm lazy. Anyway, @michalrus, is there any problem with Dwarf Fortress which needs this fix?

[michalrus]

@abbradar, none that I know of. =) I just didn’t want this hint from @ttuegel to disappear in channel’s logs.