Reduce default verbosity for running scripts

Closes #5508

cabal-install/src/Distribution/Client/CmdRun.hs

@@ -2,6 +2,7 @@
 {-# LANGUAGE NamedFieldPuns #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE RecordWildCards #-}
+{-# LANGUAGE TupleSections #-}
 
 -- | cabal-install CLI command: run
 --
@@ -43,7 +44,7 @@ import Distribution.Simple.Command
 import Distribution.Types.ComponentName
          ( showComponentName )
 import Distribution.Verbosity
-         ( normal )
+         ( normal, silent )
 import Distribution.Simple.Utils
          ( wrapText, die', info, notice )
 import Distribution.Client.ProjectPlanning
@@ -120,10 +121,12 @@ runCommand = CommandUI
 runAction :: NixStyleFlags () -> [String] -> GlobalFlags -> IO ()
 runAction flags@NixStyleFlags {..} targetAndArgs globalFlags
   = withContextAndSelectors RejectNoTargets (Just ExeKind) flags targetStr globalFlags $ \targetCtx ctx targetSelectors -> do
-    baseCtx <- case targetCtx of
-      ProjectContext             -> return ctx
-      GlobalContext              -> return ctx
-      ScriptContext path exemeta -> updateContextAndWriteProjectFile ctx path exemeta
+    (baseCtx, defaultVerbosity) <- case targetCtx of
+      ProjectContext             -> return (ctx, normal)
+      GlobalContext              -> return (ctx, normal)
+      ScriptContext path exemeta -> (, silent) <$> updateContextAndWriteProjectFile ctx path exemeta
+
+    let verbosity = fromFlagOrDefault defaultVerbosity (configVerbosity configFlags)
 
     buildCtx <-
       runProjectPreBuildPhase verbosity baseCtx $ \elaboratedPlan -> do
@@ -232,7 +235,6 @@ runAction flags@NixStyleFlags {..} targetAndArgs globalFlags
                                  elaboratedPlan
            }
   where
-    verbosity = fromFlagOrDefault normal (configVerbosity configFlags)
     (targetStr, args) = splitAt 1 targetAndArgs
 
 -- | Used by the main CLI parser as heuristic to decide whether @cabal@ was

changelog.d/pr-7851

 synopsis:  Better support for scripts
 packages: cabal-install
-prs: #7851 #7925 #7938
-issues: #7842 #7073 #6354 #6149
+prs: #7851 #7925 #7938 #7990
+issues: #7842 #7073 #6354 #6149 #5508
 
 description: {
 
@@ -14,5 +14,6 @@ description: {
 - `cabal list-bin` now works with scripts
 - The name of the generated script executable has been changed from "script" to
   "cabal-script-<your-sanitized-script-name>" for easier process management.
+- Reduce the default verbosity of scripts, so that the build output doesn't interfere with the script output.
 
 }

doc/cabal-commands.rst

@@ -489,6 +489,21 @@ A note on targets: Whenever a command takes a script target and it matches the
 name of another target, the other target is preferred. To load the script
 instead pass it as an explicit path: ./script
 
+By default, scripts are run at silent verbosity (``--verbose=0``). To show the
+build output for a script either use the command
+
+::
+
+    $ cabal v2-run --verbose=n path/to/script
+
+or the interpreter line
+
+::
+
+    #!/usr/bin/env -S cabal v2-run --verbose=n
+
+For more information see :cfg-field:`verbose`
+
 cabal v2-freeze
 ----------------