Merge remote-tracking branch 'ni/master'

2 files changed, 44 insertions, 4 deletions

diff --git a/krebs/5pkgs/simple/cabal-read.nix b/krebs/5pkgs/simple/cabal-read.nix
new file mode 100644
index 00000000..f8fc71e0
--- /dev/null
+++ b/krebs/5pkgs/simple/cabal-read.nix
@@ -0,0 +1,35 @@
+{ writeHaskellPackage }:
+
+# Because `sed -n 's/.*\<ghc-options:\s\+\(.*\)/\1/p'` is too simple.
+writeHaskellPackage "cabal-read" {
+  executables.ghc-options = {
+    extra-depends = ["Cabal"];
+    text = /* haskell */ ''
+      module Main (main) where
+      import Data.List
+      import Data.Maybe
+      import Distribution.Compiler
+      import Distribution.PackageDescription.Parsec
+      import Distribution.Types.BuildInfo
+      import Distribution.Types.CondTree
+      import Distribution.Types.Executable
+      import Distribution.Types.GenericPackageDescription
+      import Distribution.Types.UnqualComponentName
+      import Distribution.Verbosity
+      import System.Environment
+      main :: IO ()
+      main = do
+          [path, name] <- getArgs
+
+          desc <- readGenericPackageDescription normal path
+
+          case lookup (mkUnqualComponentName name) (condExecutables desc) of
+            Just exe ->
+              putStrLn . intercalate " " . fromMaybe [] . lookup GHC
+                       . options . buildInfo . condTreeData $ exe
+
+            Nothing ->
+              error ("executable " <> name <> " not found in " <> path)
+    '';
+  };
+}
diff --git a/tv/5pkgs/haskell/xmonad-tv/shell.nix b/tv/5pkgs/haskell/xmonad-tv/shell.nix
index 936e6962..6ca00bc0 100644
--- a/tv/5pkgs/haskell/xmonad-tv/shell.nix
+++ b/tv/5pkgs/haskell/xmonad-tv/shell.nix
@@ -46,7 +46,7 @@ in
       xmonad_restart() {(
         set -efu
         cd "$WORKDIR"
-        if systemctl is-active xmonad; then
+        if systemctl --quiet is-active xmonad; then
           sudo systemctl stop xmonad
           cp -b "$config_XMONAD_CACHE_DIR"/xmonad.state "$CACHEDIR"/
           echo "xmonad.state: $(cat "$CACHEDIR"/xmonad.state)"
@@ -59,9 +59,14 @@ in
 
       xmonad_yield() {(
         set -efu
-        "$xmonad" --shutdown
-        cp -b "$CACHEDIR"/xmonad.state "$config_XMONAD_CACHE_DIR"/
-        sudo systemctl start xmonad
+        if ! systemctl --quiet is-active xmonad; then
+          "$xmonad" --shutdown
+          cp -b "$CACHEDIR"/xmonad.state "$config_XMONAD_CACHE_DIR"/
+          sudo systemctl start xmonad
+        else
+          echo "xmonad.service is already running" >&2
+          exit -1
+        fi
       )}
 
       export PATH=${config.systemd.services.xmonad.path}:$PATH