I can get the package to build using the following steps:

git clone https://github.com/nomacs/nomacs.git

cd nomacs

mkdir build

cd build

guix environment --ad-hoc cmake make gcc libraw exiv2 libtiff opencv python quazip qtbase qtsvg qttools pkg-config git

cmake "../ImageLounge" "-DCMAKE_BUILD_TYPE=RelWithDebInfo" "-DCMAKE_INSTALL_PREFIX=/gnu/store/fiwxb6mlwhvnr49f9ydbhbam\
wp4bzb8b-nomacs-3.16.224" "-DCMAKE_INSTALL_LIBDIR=lib" "-DCMAKE_INSTALL_RPATH_USE_LINK_PATH=TRUE" "-DCMAKE_INSTALL_RPA\
TH=/gnu/store/fiwxb6mlwhvnr49f9ydbhbamwp4bzb8b-nomacs-3.16.224/lib" "-DCMAKE_VERBOSE_MAKEFILE=ON" "-DENABLE_TRANSLATIO\
NS=true" "-DUSE_SYSTEM_QUAZIP=true" "-DENABLE_OPENCV=true"

make -j 8

./nomacs

For some reason that is different than when `guix package --from-file` runs.

Den fre 1 jan. 2021 kl 23:02 skrev Rovanion Luckey <rovanion.luckey@gmail.com>:

Hi Leo and thank you for explaining. And hi again guix-devel.

I've now rewritten the file according to your comments except that its still its own file/module, something I'll fix later.

Now I'm stuck trying to figure out a build error after going from the tarball release through url-fetch to the non-recursive git-clone download. CMake finds the package OpenCV when it runs, removing OpenCV from the package inputs results in an error from CMake (as expected). But the build fails during the build phase with the following error:

> make[2]: *** No rule to make target 'opencv_core-NOTFOUND', needed by 'libnomacsCore.so.3.16.0'. Stop.

I've not found any relevant mentions of opencv_core in the source code. I tried adding monkeying about with the CMakeLists a little to no avail. Also looked at what Debian does to their package but found nothing that I thought to be relevant: https://sources.debian.org/src/nomacs/3.12.0+dfsg-3/debian/

I've attached the new package source.