System.Process.Read/Run: Haddock thrown exceptions

This documentation matters for catching exceptions later, and to make
sure we're catching all exceptions we need to.

Some of the documentation turned out to be incorrect.

src/System/Process/Read.hs

@@ -142,6 +142,8 @@ envHelper :: EnvOverride -> Maybe [(String, String)]
 envHelper = Just . eoStringList
 
 -- | Read from the process, ignoring any output.
+--
+-- Throws a 'ReadProcessException' exception if the process fails.
 readProcessNull :: (MonadIO m, MonadLogger m, MonadBaseControl IO m, MonadCatch m)
                 => Maybe (Path Abs Dir) -- ^ Optional working directory
                 -> EnvOverride
@@ -215,6 +217,8 @@ instance Exception ReadProcessException
 -- If the process fails, spits out stdout and stderr as error log
 -- level. Should not be used for long-running processes or ones with
 -- lots of output; for that use 'sinkProcessStdoutLogStderr'.
+--
+-- Throws a 'ReadProcessException' if unsuccessful.
 sinkProcessStdout
     :: (MonadIO m, MonadLogger m, MonadBaseControl IO m, MonadCatch m)
     => Maybe (Path Abs Dir) -- ^ Optional directory to run in
@@ -258,6 +262,8 @@ logProcessStderrStdout mdir name menv args = liftBaseWith $ \restore -> do
     void $ restore $ sinkProcessStderrStdout mdir menv name args logLines logLines
 
 -- | Consume the stdout and stderr of a process feeding strict 'S.ByteString's to the consumers.
+--
+-- Throws a 'ReadProcessException' if unsuccessful in launching, or 'ProcessExitedUnsuccessfully' if the process itself fails.
 sinkProcessStderrStdout :: forall m e o. (MonadIO m, MonadLogger m)
                         => Maybe (Path Abs Dir) -- ^ Optional directory to run in
                         -> EnvOverride
@@ -277,6 +283,8 @@ sinkProcessStderrStdout wd menv name args sinkStderr sinkStdout = do
     f err out = (err $$ sinkStderr) `concurrently` (out $$ sinkStdout)
 
 -- | Like sinkProcessStderrStdout, but receives Handles for stderr and stdout instead of 'Sink's.
+--
+-- Throws a 'ReadProcessException' if unsuccessful in launching, or 'ProcessExitedUnsuccessfully' if the process itself fails.
 sinkProcessStderrStdoutHandle :: (MonadIO m, MonadLogger m)
                               => Maybe (Path Abs Dir) -- ^ Optional directory to run in
                               -> EnvOverride
@@ -299,6 +307,8 @@ sinkProcessStderrStdoutHandle wd menv name args err out = do
 
 -- | Perform pre-call-process tasks.  Ensure the working directory exists and find the
 -- executable path.
+--
+-- Throws a 'ReadProcessException' if unsuccessful.
 preProcess :: (MonadIO m)
   => Maybe (Path Abs Dir) -- ^ Optional directory to create if necessary
   -> EnvOverride       -- ^ How to override environment

src/System/Process/Run.hs

@@ -85,15 +85,15 @@ runCmd' modCP cmd@(Cmd{..}) mbErrMsg = do
 
 -- | Like 'System.Process.callProcess', but takes an optional working directory and
 -- environment override, and throws 'ProcessExitedUnsuccessfully' if the
--- process exits unsuccessfully.
+-- process exits unsuccessfully and a 'ReadProcessException' if the executable is not found.
 --
 -- Inherits stdout and stderr.
 callProcess :: (MonadIO m, MonadLogger m) => Cmd -> m ()
 callProcess = callProcess' id
 
 -- | Like 'System.Process.callProcess', but takes an optional working directory and
 -- environment override, and throws 'ProcessExitedUnsuccessfully' if the
--- process exits unsuccessfully.
+-- process exits unsuccessfully and a 'ReadProcessException' if the executable is not found.
 --
 -- Inherits stdout and stderr.
 callProcess' :: (MonadIO m, MonadLogger m)
@@ -140,6 +140,7 @@ createProcess' tag modCP cmd = do
     $logCreateProcess c
     liftIO $ System.Process.createProcess_ tag c
 
+-- Throws a 'ReadProcessException' if process is not found.
 cmdToCreateProcess :: MonadIO m => Cmd -> m CreateProcess
 cmdToCreateProcess (Cmd wd cmd0 menv args) = do
     cmd <- preProcess wd menv cmd0