Add notice about closing stdout/stderr file descriptors to style.md

diff --git a/doc/dev/style.md b/doc/dev/style.md
index 8c74dcebce9e7d309e4ebbede72d92c775fb6e38..45c481eb90f57bb424036b72566843d17f9d347d 100644 (file)
--- a/doc/dev/style.md
+++ b/doc/dev/style.md
@@ -761,4 +761,6 @@ Bash should be avoided.  Some pitfalls to avoid:
   statement, or use `"cat << EOF"`.
 * To set a variable from outside awk, use `"awk '{...}' var=value"` rather
   than `"awk -vvar=value '{...}'"`
-
+* Don't close stdout/stderr descriptors (`>&-`), but redirect them to /dev/null
+  instead (`>/dev/null`) as the closed descriptor might get reused leading to
+  unpredictable behaviour when using `fprintf(stderr, ...)`