guile: Fix random test failure

Also, let's try parallel building again. Seems to work on several
tries.

https://debbugs.gnu.org/cgi/bugreport.cgi?bug=24769#12

http://hydra.nixos.org/build/43385084

pkgs/development/interpreters/guile/default.nix

@@ -16,8 +16,8 @@
 
   nativeBuildInputs = [ makeWrapper gawk pkgconfig ];
   buildInputs = [ readline libtool libunistring libffi ];
-  propagatedBuildInputs = [ gmp boehmgc ]
 
+  propagatedBuildInputs = [ gmp boehmgc ]
     # XXX: These ones aren't normally needed here, but since
     # `libguile-2.0.la' reads `-lltdl -lunistring', adding them here will add
     # the needed `-L' flags.  As for why the `.la' file lacks the `-L' flags,
@@ -27,11 +27,9 @@
   # A native Guile 2.0 is needed to cross-build Guile.
   selfNativeBuildInput = true;
 
-  # Guile 2.0.11 repeatable fails with 8-core parallel building because
+  enableParallelBuilding = true;
-  # libguile/vm-i-system.i is not created in time
-  enableParallelBuilding = false;
 
-  patches = [ ./disable-gc-sensitive-tests.patch ./eai_system.patch ./clang.patch ] ++
+  patches = [ ./disable-gc-sensitive-tests.patch ./eai_system.patch ./clang.patch ./fix-test.patch ] ++
     (stdenv.lib.optional (coverageAnalysis != null) ./gcov-file-name.patch);
 
   # Explicitly link against libgcc_s, to work around the infamous

pkgs/development/interpreters/guile/fix-test.patch

@@ -0,0 +1,38 @@
+From 2fbde7f02adb8c6585e9baf6e293ee49cd23d4c4 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Ludovic=20Court=C3=A8s?= <ludo@gnu.org>
+Date: Fri, 4 Nov 2016 22:45:51 +0100
+Subject: tests: Avoid race condition in REPL server test.
+
+Fixes <http://bugs.gnu.org/24769>.
+Reported by Rob Browning <rlb@defaultvalue.org>.
+
+* test-suite/tests/00-repl-server.test ("simple expression"): Add call
+to 'select' before 'display'.
+---
+ test-suite/tests/00-repl-server.test | 10 ++++++++--
+ 1 file changed, 8 insertions(+), 2 deletions(-)
+
+diff --git a/test-suite/tests/00-repl-server.test b/test-suite/tests/00-repl-server.test
+index 1f570a9..4b5ec0c 100644
+--- a/test-suite/tests/00-repl-server.test
++++ b/test-suite/tests/00-repl-server.test
+@@ -105,8 +105,14 @@ reached."
+       "scheme@(repl-server)> $1 = 42\n"
+     (with-repl-server socket
+       (read-until-prompt socket %last-line-before-prompt)
+-      (display "(+ 40 2)\n(quit)\n" socket)
+-      (read-string socket)))
++
++      ;; Wait until 'repl-reader' in boot-9 has written the prompt.
++      ;; Otherwise, if we write too quickly, 'repl-reader' checks for
++      ;; 'char-ready?' and doesn't print the prompt.
++      (match (select (list socket) '() (list socket) 3)
++        (((_) () ())
++         (display "(+ 40 2)\n(quit)\n" socket)
++         (read-string socket)))))
+ 
+   (pass-if "HTTP inter-protocol attack"           ;CVE-2016-8606
+     (with-repl-server socket
+-- 
+cgit v1.0
+