bin/mdw-build: Make a note of the persistent file-descriptor assignments.

It's a little fiddly to work out each time.

diff --git a/bin/mdw-build b/bin/mdw-build
index 45ca7f8b9c9825b1d0822c76cd69ca9032063d8e..7c825243ffbcea5488c4b85c21f83381ca84af24 100755 (executable)
--- a/bin/mdw-build
+++ b/bin/mdw-build
@@ -184,6 +184,15 @@ case $jobs in 1) ;; *) makeopts="$makeopts -j$jobs" ;; esac
 ###--------------------------------------------------------------------------
 ### Utility functions.
 
+## File descriptor assignments:
+##
+##    0 -- original stdin (never touched)
+## 1, 2 -- stdout, stderr, redirected to 3 while running comamnds
+##    3 -- original stderr (verbose), or logfile (quiet); captures command
+##             output
+##    4 -- null (verbose), or logfile (quiet); primary diagnostic output
+##    5 -- orginal stderr; secondary diagnostic output (with colours)
+
 exec 3>&2 4>/dev/null 5>&2
 
 notify () {