gnu: Add python-3.8.

* gnu/packages/python.scm (python-3.8): New public variable.
[source]: Add patches to skip four tests.
* gnu/packages/patches/python-3.8-search-paths.patch: New file.
* gnu/packages/patches/python-3.8-fix-tests.patch: New file.

Signed-off-by: Marius Bakke <mbakke@fastmail.com>

gnu/packages/patches/python-3.8-fix-tests.patch

@@ -0,0 +1,42 @@
+diff --git a/Lib/test/_test_multiprocessing.py b/Lib/test/_test_multiprocessing.py
+index 1474624..887f8ee 100644
+--- a/Lib/test/_test_multiprocessing.py
++++ b/Lib/test/_test_multiprocessing.py
+@@ -3801,6 +3801,7 @@ class _TestSharedMemory(BaseTestCase):
+         sms.close()
+
+     @unittest.skipIf(os.name != "posix", "not feasible in non-posix platforms")
++    @unittest.skipUnless(sys.stdin.isatty(), "KeyboardInterrupts require a TTY device")
+     def test_shared_memory_SharedMemoryServer_ignores_sigint(self):
+         # bpo-36368: protect SharedMemoryManager server process from
+         # KeyboardInterrupt signals.
+diff --git a/Lib/test/test_signal.py b/Lib/test/test_signal.py
+index d41e94b..a1c15e7 100644
+--- a/Lib/test/test_signal.py
++++ b/Lib/test/test_signal.py
+@@ -78,6 +78,7 @@ class PosixTests(unittest.TestCase):
+         self.assertLess(len(s), signal.NSIG)
+
+     @unittest.skipUnless(sys.executable, "sys.executable required.")
++    @unittest.skipUnless(sys.stdin.isatty(), "KeyboardInterrupts require a TTY device")
+     def test_keyboard_interrupt_exit_code(self):
+         """KeyboardInterrupt triggers exit via SIGINT."""
+         process = subprocess.run(
+@@ -128,6 +129,7 @@ class WindowsSignalTests(unittest.TestCase):
+             signal.signal(7, handler)
+
+     @unittest.skipUnless(sys.executable, "sys.executable required.")
++    @unittest.skipUnless(sys.stdin.isatty(), "KeyboardInterrupts require a TTY device")
+     def test_keyboard_interrupt_exit_code(self):
+         """KeyboardInterrupt triggers an exit using STATUS_CONTROL_C_EXIT."""
+         # We don't test via os.kill(os.getpid(), signal.CTRL_C_EVENT) here
+@@ -1245,6 +1247,7 @@ class StressTest(unittest.TestCase):
+
+ class RaiseSignalTest(unittest.TestCase):
+
++    @unittest.skipUnless(sys.stdin.isatty(), "KeyboardInterrupts require a TTY device")
+     def test_sigint(self):
+         with self.assertRaises(KeyboardInterrupt):
+             signal.raise_signal(signal.SIGINT)
+--
+2.23.0

gnu/packages/patches/python-3.8-search-paths.patch

@@ -0,0 +1,17 @@
+diff --git a/setup.py b/setup.py
+index 20d7f35..5751083 100644
+--- a/setup.py
++++ b/setup.py
+@@ -676,8 +676,8 @@ class PyBuildExt(build_ext):
+         # if a file is found in one of those directories, it can
+         # be assumed that no additional -I,-L directives are needed.
+         if not CROSS_COMPILING:
+-            self.lib_dirs = self.compiler.library_dirs + system_lib_dirs
+-            self.inc_dirs = self.compiler.include_dirs + system_include_dirs
++            self.lib_dirs = os.getenv('LIBRARY_PATH', '').split(os.pathsep)
++            self.inc_dirs = os.getenv('CPATH', '').split(os.pathsep)
+         else:
+             # Add the sysroot paths. 'sysroot' is a compiler option used to
+             # set the logical path of the standard system headers and
+--
+2.23.0

gnu/packages/python.scm

@@ -57,6 +57,7 @@
 ;;; Copyright © 2018, 2019 Maxim Cournoyer <maxim.cournoyer@gmail.com>
 ;;; Copyright © 2018 Luther Thompson <lutheroto@gmail.com>
 ;;; Copyright © 2018 Vagrant Cascadian <vagrant@debian.org>
+;;; Copyright © 2019 Tanguy Le Carrour <tanguy@bioneland.org>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -408,6 +409,31 @@ (define-public python-3.7
                                         (version-major+minor version)
                                         "/site-packages"))))))))
 
+(define-public python-3.8
+  (package
+    (inherit python-3.7)
+    (name "python-next")
+    (version "3.8.0")
+    (source
+     (origin
+       (inherit (package-source python-3.7))
+       (uri (string-append "https://www.python.org/ftp/python/"
+                           version "/Python-" version ".tar.xz"))
+       (sha256 (base32 "110d0did9rxn7rg85kf2fwli5hqq44xv2d8bi7d92m7v2d728mmk"))
+       (patches (search-patches
+                 "python-3.8-search-paths.patch"
+                 "python-3-fix-tests.patch"
+                 "python-3.8-fix-tests.patch"
+                 "python-3-deterministic-build-info.patch"))
+       (snippet
+        '(begin
+           ;; Delete the bundled copy of libexpat.
+           (delete-file-recursively "Modules/expat")
+           (substitute* "Modules/Setup"
+             ;; Link Expat instead of embedding the bundled one.
+             (("^#pyexpat.*") "pyexpat pyexpat.c -lexpat\n"))
+           #t))))))
+
 ;; Current 3.x version.
 (define-public python-3 python-3.7)