Initial commit

pkgs/fetchers.nix

@@ -0,0 +1,43 @@
+{ lib
+, runCommand
+, findutils
+, gdown
+}:
+let
+
+  mkFetcher = mkCmd: {
+    name ? "source",
+    assert_exists ? [],
+    url,
+    hash ? lib.fakeHash,
+    preferLocalBuild ? true,
+  }: runCommand name {
+    outputHash = if hash == "" || hash == null then lib.fakeHash else hash;
+    outputHashAlgo = null;
+    outputHashMode = "recursive";
+    inherit preferLocalBuild;
+    passthru = { inherit url; };
+  } ''
+    cd $(mktemp -d)
+    ${mkCmd url}
+    ${lib.concatMapStringsSep "\n" (fname: ''
+      if ! test -s ${lib.escapeShellArg fname}; then
+        echo ERROR: file not found: ${lib.escapeShellArg fname}
+        echo Files found:
+        ${findutils}/bin/find .
+        false
+      fi
+    '') assert_exists}
+    if test $(ls | wc -l) -gt 1; then
+      mkdir $out
+    fi
+    cp -v * $out
+  '';
+
+in {
+
+  fetchFromDrive = mkFetcher (url:
+    "HOME=$(mktemp -d) ${gdown}/bin/gdown ${lib.escapeShellArg url}"
+  );
+
+}