py3: cysignals fails its test suite

[jhpalmieri]

With a Python 3 build of Sage, ./sage -f -c cysignals fails because the test suite doesn't use the correct version of Python.

CC: @jdemeyer

Component: packages: standard

Author: John Palmieri

Branch/Commit: f4f3c86

Reviewer: Volker Braun

Issue created by migration from https://trac.sagemath.org/ticket/28726

[jhpalmieri]

comment:1

The change

diff --git a/build/pkgs/cysignals/spkg-check b/build/pkgs/cysignals/spkg-check
index c94041e096..37fa0dddfc 100644
--- a/build/pkgs/cysignals/spkg-check
+++ b/build/pkgs/cysignals/spkg-check
@@ -4,4 +4,4 @@ if [ -z "$SAGE_LOCAL" ]; then
     exit 1
 fi
 
-cd src && $MAKE check-install
+cd src && $MAKE check-install PYTHON=sage-python23

helps testing get started, but the test suite still fails on OS X. I see this message in the log file:

Traceback (most recent call last):
  File "rundoctests.py", line 74, in <module>
    resource.setrlimit(resource.RLIMIT_STACK, (stacksize, stacksize))
ValueError: current limit exceeds maximum limit

[vbraun]

comment:2

I'm seeing that one, too. Only admins can increase the stack size, there is nothing that the testsuite can do about it (except not running the test, does it really need that big a stack?)

[vbraun]

comment:4

Maybe you can turn your diff already into a patch, we should surely be using the correct python version.

[jhpalmieri]

Branch: u/jhpalmieri/cysignals-python-version

[jhpalmieri]

Commit: f4f3c86

[jhpalmieri]

comment:6

I don't understand the stack size issue. The following patch is a bad idea since it completely disables the stack size limitation put in by cysignals' rundoctests.py, but with it, the test suite passes for me with OS X + py3:

diff --git a/build/pkgs/cysignals/patches/stacksize.patch b/build/pkgs/cysignals/patches/stacksize.patch
new file mode 100644
index 0000000000..63a11ba07f
--- /dev/null
+++ b/build/pkgs/cysignals/patches/stacksize.patch
@@ -0,0 +1,13 @@
+diff --git a/rundoctests.py b/rundoctests.py
+index 94d58e1..3c4f8c3 100755
+--- a/rundoctests.py
++++ b/rundoctests.py
+@@ -71,7 +71,7 @@ if os.name != 'nt':
+     import resource
+     # Limit stack size to avoid errors in stack overflow doctest
+     stacksize = 1 << 20
+-    resource.setrlimit(resource.RLIMIT_STACK, (stacksize, stacksize))
++    # resource.setrlimit(resource.RLIMIT_STACK, (stacksize, stacksize))
+ 
+     # Disable core dumps
+     resource.setrlimit(resource.RLIMIT_CORE, (0, 0))

---

New commits:

f4f3c86

trac 28726: use the correct version of Python in cysignals spkg-check

[jhpalmieri]

comment:7

I'm not marking this ready for review, because even with the patch specifying the correction version of Python, it doesn't pass its test suite.

[jhpalmieri]

comment:8

On the other hand, with just this patch, tests do pass on my ubuntu virtual machine. So maybe the stack size issue is OS X only?

[vbraun]

comment:9

So we are trying to reduce the stack size, not increase it. 1MB is pretty low. Whats the output of ulimit -s on your OSX machine? I think its 8192 (8MB) by default, which should be plenty. I don't get an error running:

OSX:~ vbraun$ python
Python 2.7.10 (default, Feb 22 2019, 21:55:15) 
[GCC 4.2.1 Compatible Apple LLVM 10.0.1 (clang-1001.0.37.14)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import resource
>>> resource.getrlimit(resource.RLIMIT_STACK)
(8388608, 67104768)
>>> stacksize = 1 << 20
>>> resource.setrlimit(resource.RLIMIT_STACK, (stacksize, stacksize))
>>> resource.getrlimit(resource.RLIMIT_STACK)
(1048576, 1048576)

[jhpalmieri]

comment:10

ulimit -s returns 8192. I don't get an error running that with Python 2, but I do with Python 3 on OS X. (On the Ubuntu virtual machine, I don't get an error with Python 3.)

[jhpalmieri]

comment:11

$ python
Python 2.7.16 (default, Oct 16 2019, 00:34:56) 
[GCC 4.2.1 Compatible Apple LLVM 10.0.1 (clang-1001.0.37.14)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import resource
>>> resource.getrlimit(resource.RLIMIT_STACK)
(8388608, 67104768)
>>> stacksize = 1 << 20
>>> resource.setrlimit(resource.RLIMIT_STACK, (stacksize, stacksize))
>>> resource.getrlimit(resource.RLIMIT_STACK)
(1048576, 1048576)

and

$ sage --python
Python 3.7.3 (default, Nov  5 2019, 10:19:31) 
[Clang 11.0.0 (clang-1100.0.33.12)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import resource
>>> resource.getrlimit(resource.RLIMIT_STACK)
(8388608, 67104768)
>>> stacksize = 1 << 20
>>> resource.setrlimit(resource.RLIMIT_STACK, (stacksize, stacksize))
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: current limit exceeds maximum limit

I get the same error if I use python3, but I forget how I installed Python 3 on this machine.

[jhpalmieri]

comment:12

Is this a recurrence of sagemath/cysignals#71?

[jhpalmieri]

comment:13

Or maybe it's https://bugs.python.org/issue34602, and upgrading Python will help.

[jhpalmieri]

comment:14

I installed Python 3.7.5, and I still hit this problem.

[vbraun]

comment:15

Do you mind opening a cysignals issue for the OSX kernel oddity / bug? The ValueError should probably just be caught and discarded. But we could merge this in the meantime...

[vbraun]

Author: John Palmieri

[vbraun]

Reviewer: Volker Braun

[jhpalmieri]

comment:17

Okay, I opened up a cysignals issue.

[vbraun]

comment:18

Thanks! Bug is at sagemath/cysignals#118 for future historians ;-)

[vbraun]

Changed branch from u/jhpalmieri/cysignals-python-version to f4f3c86