orca-slicer: get rid of osmesa dependency, clean up other mesa-related things

It's not actually necessary.

pkgs/by-name/or/orca-slicer/package.nix

@@ -27,7 +27,6 @@
   hicolor-icon-theme,
   ilmbase,
   libpng,
-  mesa,
   mpfr,
   nlopt,
   opencascade-occt_7_6,
@@ -107,9 +106,6 @@ stdenv.mkDerivation rec {
       hicolor-icon-theme
       ilmbase
       libpng
-      mesa
-      mesa.osmesa
-      mesa.drivers
       mpfr
       nlopt
       opencascade-occt_7_6
@@ -129,6 +125,8 @@ stdenv.mkDerivation rec {
     ./patches/0001-not-for-upstream-CMakeLists-Link-against-webkit2gtk-.patch
     # Link opencv_core and opencv_imgproc instead of opencv_world
     ./patches/dont-link-opencv-world-orca.patch
+    # Don't link osmesa
+    ./patches/no-osmesa.patch
     # The changeset from https://github.com/SoftFever/OrcaSlicer/pull/7650, can be removed when that PR gets merged
     # Allows disabling the update nag screen
     (fetchpatch {
@@ -169,8 +167,6 @@ stdenv.mkDerivation rec {
 
   NIX_LDFLAGS = toString [
     (lib.optionalString withSystemd "-ludev")
-    "-L${mesa.osmesa}/lib"
-    "-L${mesa.drivers}/lib"
     "-L${boost186}/lib"
     "-lboost_log"
     "-lboost_log_setup"
@@ -194,7 +190,6 @@ stdenv.mkDerivation rec {
     "-DBOOST_LOG_NO_LIB=OFF"
     "-DCMAKE_CXX_FLAGS=-DGL_SILENCE_DEPRECATION"
     "-DCMAKE_EXE_LINKER_FLAGS=-Wl,--no-as-needed"
-    "-DCMAKE_EXE_LINKER_FLAGS=-Wl,-rpath,${mesa.drivers}/lib -Wl,-rpath,${mesa.osmesa}/lib"
     "-DORCA_VERSION_CHECK_DEFAULT=OFF"
   ];
 
@@ -202,12 +197,9 @@ stdenv.mkDerivation rec {
     gappsWrapperArgs+=(
       --prefix LD_LIBRARY_PATH : "$out/lib:${
         lib.makeLibraryPath [
-          mesa.drivers
-          mesa.osmesa
           glew
         ]
       }"
-      --prefix LIBGL_DRIVERS_PATH : "${mesa.drivers}/lib/dri"
       --set WEBKIT_DISABLE_COMPOSITING_MODE 1
     )
   '';

pkgs/by-name/or/orca-slicer/patches/no-osmesa.patch

@@ -0,0 +1,13 @@
+diff --git a/src/slic3r/CMakeLists.txt b/src/slic3r/CMakeLists.txt
+index e695acd48..174e233e6 100644
+--- a/src/slic3r/CMakeLists.txt
++++ b/src/slic3r/CMakeLists.txt
+@@ -587,7 +587,7 @@ elseif (CMAKE_SYSTEM_NAME STREQUAL "Linux")
+     FIND_LIBRARY(WAYLAND_EGL_LIBRARIES    NAMES wayland-egl)
+     FIND_LIBRARY(WAYLAND_CLIENT_LIBRARIES NAMES wayland-client)
+     find_package(CURL REQUIRED)
+-    target_link_libraries(libslic3r_gui ${DBUS_LIBRARIES} OSMesa)
++    target_link_libraries(libslic3r_gui ${DBUS_LIBRARIES})
+     target_link_libraries(libslic3r_gui
+         OpenGL::EGL
+         ${WAYLAND_SERVER_LIBRARIES}