eloquent: foonathan-memory-vendor: work around the poorly designed build system

eloquent/overrides.nix

@@ -2,4 +2,22 @@
 self:
 # Distro package set
 rosSelf: rosSuper: with rosSelf.lib; {
+  # This build system contains fractal levels of stupidity
+  foonathan-memory-vendor = patchVendorGit rosSuper.foonathan-memory-vendor {
+    url = "https://github.com/foonathan/memory.git";
+    sha256 = "1n7xxi61wzpixb3kldnl826syb4yml613q4i38d0cciydhy1gwzl";
+    fetchgitArgs = {
+      # Needed by the postFetch, then removed there
+      leaveDotGit = true;
+      # Prevent the build system from trying to download random files
+      postFetch = ''
+        cd "$out/cmake/comp"
+        git fetch https://github.com/foonathan/compatibility.git
+        git checkout -f cf13bff238397aab0d8c49b7f6263233cf8a2396
+        sed -i 's|\(set(COMP_REMOTE_URL\s\).*|\1"file://''${CMAKE_CURRENT_LIST_DIR}/")|' \
+          comp_base.cmake
+        rm -rf "$out/.git"
+      '';
+    };
+  };
 }

kinetic/overrides.nix

@@ -13,7 +13,7 @@ rosSelf: rosSuper: with rosSelf.lib; {
     ];
   });
 
-  # If anyone actually needs this package, its your problem to get it to
+  # If anyone actually needs this package, it's your problem to get it to
   # compile.
   astra-camera = null;
 

lib/default.nix

@@ -16,6 +16,20 @@ with lib;
     '' + postPatch;
   });
 
+  patchVendorGit = pkg: {
+    url, sha256,
+    file ? "CMakeLists.txt",
+    fetchgitArgs ? {}
+  }: pkg.overrideAttrs ({
+    postPatch ? "", ...
+  }: {
+    postPatch = ''
+      sed -i '\|GIT_REPOSITORY\s.*${escapeShellArg url}|c\
+        URL "${self.fetchgit ({ inherit url sha256; } // fetchgitArgs)}"' \
+        '${file}'
+    '' + postPatch;
+  });
+
   patchBoostPython = pkg: pkg.overrideAttrs ({
     postPatch ? "", ...
   }: {