diff -ru bash-5.1.orig/configure bash-5.1/configure

--- bash-5.1.orig/configure	2020-12-04 15:05:14.000000000 +0100

+++ bash-5.1/configure	2020-12-08 14:34:05.162114735 +0100

@@ -2917,6 +2917,7 @@

 *-nsk*)		opt_bash_malloc=no ;;	# HP NonStop

 *-haiku*)	opt_bash_malloc=no ;;	# Haiku OS

 *-genode*)	opt_bash_malloc=no ;;	# Genode has no sbrk

+*-midipix*)	opt_bash_malloc=no ;;	# Midipix

 esac

 # memory scrambling on free()

diff -ru bash-5.1.orig/lib/sh/oslib.c bash-5.1/lib/sh/oslib.c

--- bash-5.1.orig/lib/sh/oslib.c	2013-10-14 15:12:57.000000000 +0200

+++ bash-5.1/lib/sh/oslib.c	2020-12-08 14:35:05.062112859 +0100

@@ -280,7 +280,7 @@

 long

 getmaxchild ()

 {

-  static long maxchild = -1L;

+  static long maxchild = _SC_CHILD_MAX;

   if (maxchild > 0)

     return maxchild;

--- bash-5.1.8/builtins/psize.sh.orig	2013-10-14 15:14:35.000000000 +0200

+++ bash-5.1.8/builtins/psize.sh	2021-08-19 09:16:16.724336836 +0200

@@ -1,21 +1,6 @@

 #! /bin/sh

 #

-# psize.sh -- determine this system's pipe size, and write a define to

-#             pipesize.h so ulimit.c can use it.

-

-: ${TMPDIR:=/tmp}

-# try to use mktemp(1) if the system supports it

-{ TMPFILE="`mktemp $TMPDIR/pipsize.XXXXXX 2>/dev/null`"; } 2>/dev/null

-used_mktemp=true

-

-if [ -z "$TMPFILE" ]; then

-	TMPNAME=pipsize.$$

-	TMPFILE=$TMPDIR/$TMPNAME

-	used_mktemp=false

-fi

-

-trap 'rm -f "$TMPFILE" ; exit 1' 1 2 3 6 15

-trap 'rm -f "$TMPFILE"' 0

+# psize.sh -- write midipix' pipe size define to pipesize.h so ulimit.c can use it.

 echo "/*"

 echo " * pipesize.h"

@@ -24,22 +9,6 @@

 echo " * Do not edit!"

 echo " */"

 echo ""

-

-#

-# Try to avoid tempfile races.  We can't really check for the file's

-# existence before we run psize.aux, because `test -e' is not portable,

-# `test -h' (test for symlinks) is not portable, and `test -f' only

-# checks for regular files.  If we used mktemp(1), we're ahead of the

-# game.

-#

-$used_mktemp || rm -f "$TMPFILE"

-

-./psize.aux 2>"$TMPFILE" | sleep 3

-

-if [ -s "$TMPFILE" ]; then

-	echo "#define PIPESIZE `cat "$TMPFILE"`"

-else

-	echo "#define PIPESIZE 512"

-fi

+echo "#define PIPESIZE 512"

 exit 0