CMAKE_INSTALL_DOCDIR set incorrectly without multiple outputs

[jtojnar]

CMake’s GNUInstallDirs module expects CMAKE_INSTALL_DOCDIR variable to contain the project name.

The issue is that $shareDocName used by the setup hook

nixpkgs/pkgs/development/tools/build-managers/cmake/setup-hook.sh

Line 80 in 6bba942

cmakeFlags="-DCMAKE_INSTALL_DOCDIR=${!outputDoc}/share/doc/${shareDocName} $cmakeFlags"

is only defined when using multiple outputs:

nixpkgs/pkgs/build-support/setup-hooks/multiple-outputs.sh

Lines 55 to 67 in 6bba942

	if [ -z "$shareDocName" ]; then
	local confScript="$configureScript"
	if [ -z "$confScript" ] && [ -x ./configure ]; then
	confScript=./configure
	fi
	if [ -f "$confScript" ]; then
	local shareDocName="$(sed -n "s/^PACKAGE_TARNAME='\(.*\)'$/\1/p" < "$confScript")"
	fi
	# PACKAGE_TARNAME sometimes contains garbage.
	if [ -n "$shareDocName" ] || echo "$shareDocName" | grep -q '[^a-zA-Z0-9_-]'; then
	shareDocName="$(echo "$name" | sed 's/-[^a-zA-Z].*//')"
	fi
	fi

[jtojnar]

Actually, the variable does not seem to be set even with multiple outputs. Which makes sense since there is no configure script.

[jtojnar]

The issue would actually be that, since this package sets pname instead of name, shareDocName is falling back to an empty string. Edit: mkDerivation creates name as well since it is actually needed by derivation construct.

Though here _multioutConfig does not even run since the CMake setup hook makes it return immediately:

nixpkgs/pkgs/development/tools/build-managers/cmake/setup-hook.sh

Line 118 in 6bba942

setOutputFlags=

nixpkgs/pkgs/build-support/setup-hooks/multiple-outputs.sh

Line 50 in 6bba942

if [ "$outputs" = "out" ] || [ -z "${setOutputFlags-1}" ]; then return; fi;

[jtojnar]

Asked on StackOverflow about the best way to continue:

https://stackoverflow.com/q/60631865/160386

[doronbehar]

Asked on StackOverflow about the best way to continue:

Perhaps this question is more appropriate for https://discourse.cmake.org/ ?

[jtojnar]

The change was actually reverted, #93166 is a proper fix.