From a56e8f0a877b792f0da114e4fbc3fcee9598e11a Mon Sep 17 00:00:00 2001
From: Janneke Nieuwenhuizen <janneke@gnu.org>
Date: Sat, 16 Nov 2024 20:21:59 +0100
Subject: [PATCH] gnu: bash: Avoid hang when cross-built for the Hurd.

For example, without this patch bash hangs while configuring diffutils.
Reproducer:

cat >x.awk <<EOF
x... repeat 16384 (the actual pipe size) times
EOF

* gnu/packages/bash.scm (bash): When cross-building for the Hurd, add new
"create-pipesize.h" stage.

Change-Id: I02c1dcf2d63849626ba3448cd52766db822dc77c
---
 gnu/packages/bash.scm | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/gnu/packages/bash.scm b/gnu/packages/bash.scm
index 56918d79bd3..642a4059852 100644
--- a/gnu/packages/bash.scm
+++ b/gnu/packages/bash.scm
@@ -175,6 +175,20 @@ number/base32-hash tuples, directly usable in the 'patch-series' form."
 
         #:phases
         (modify-phases %standard-phases
+          ,@(if (and (target-hurd?) (not (system-hurd?)))
+                `((add-after 'configure 'create-pipesize.h
+                    ;; The Bash Makefile mentions how PIPESIZE calculation is
+                    ;; "technically wrong" when cross-compiling, and offers no
+                    ;; way to override it.  On the 64bit Hurd, it can make
+                    ;; bash hang.
+                    (lambda _
+                      (with-directory-excursion "builtins"
+                        (with-output-to-file "psize.aux"
+                          (lambda _ (display "dummy to pacify make\n")))
+                        (with-output-to-file "pipesize.h"
+                          (lambda _ (display "#define PIPESIZE 16384\n")))))))
+                '())
+
           (add-after 'install 'install-sh-symlink
             (lambda* (#:key outputs #:allow-other-keys)
               ;; Add a `sh' -> `bash' link.