[sage-devel] Re: ImportError: This platform lacks a functioning sem_open implementation, ... see issue 3770

[Kamil Pliszka]

Hi,
Thx for your suggestion, in python2-2.7.13.p0.log I've found:
"checking whether POSIX semaphores are enabled... no"
It seems that python compiled without semaphores, but error comes 
from sagelib-7.6 package.
It looks that /dev/shm was disabled on my box(when I was compiling 
python27), then I enabled seamphores, and after that run again make - so it 
started from building sagelib(python was still compiled without semaphores).

I've cleaned previous build, started building again, and works fine.
Greets.

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[sage-devel] ImportError: This platform lacks a functioning sem_open implementation, ... see issue 3770

[Kamil Pliszka]

Hi,
I have problem when compiling sage7.6:

...
[sagelib-7.6] building 'sage.tests.stl_vector' extension
[sagelib-7.6] building 'sage.tests.cython' extension
[sagelib-7.6] Executing 454 commands (using 1 thread)
[sagelib-7.6] 

[sagelib-7.6] Traceback (most recent call last):
[sagelib-7.6]   File "setup.py", line 768, in 
[sagelib-7.6] ext_modules = ext_modules)
[sagelib-7.6]   File 
"/usr/local/src/sage-7.6/local/lib/python/distutils/core.py", line 151, in 
setup
[sagelib-7.6] dist.run_commands()
[sagelib-7.6]   File 
"/usr/local/src/sage-7.6/local/lib/python/distutils/dist.py", line 953, in 
run_commands
[sagelib-7.6] self.run_command(cmd)
[sagelib-7.6]   File 
"/usr/local/src/sage-7.6/local/lib/python/distutils/dist.py", line 972, in 
run_command
[sagelib-7.6] cmd_obj.run()
[sagelib-7.6]   File 
"/usr/local/src/sage-7.6/local/lib/python/distutils/command/build.py", line 
127, in run
[sagelib-7.6] self.run_command(cmd_name)
[sagelib-7.6]   File 
"/usr/local/src/sage-7.6/local/lib/python/distutils/cmd.py", line 326, in 
run_command
[sagelib-7.6] self.distribution.run_command(command)
[sagelib-7.6]   File 
"/usr/local/src/sage-7.6/local/lib/python/distutils/dist.py", line 972, in 
run_command
[sagelib-7.6] cmd_obj.run()
[sagelib-7.6]   File 
"/usr/local/src/sage-7.6/local/lib/python/distutils/command/build_ext.py", 
line 340, in run
[sagelib-7.6] self.build_extensions()
[sagelib-7.6]   File "setup.py", line 514, in build_extensions
[sagelib-7.6] execute_list_of_commands(compile_commands)
[sagelib-7.6]   File "setup.py", line 316, in execute_list_of_commands
[sagelib-7.6] execute_list_of_commands_in_parallel(command_list, 
nthreads)
[sagelib-7.6]   File "setup.py", line 263, in 
execute_list_of_commands_in_parallel
[sagelib-7.6] pool = Pool(nthreads)
[sagelib-7.6]   File 
"/usr/local/src/sage-7.6/local/lib/python/multiprocessing/__init__.py", 
line 232, in Pool
[sagelib-7.6] return Pool(processes, initializer, initargs, 
maxtasksperchild)
[sagelib-7.6]   File 
"/usr/local/src/sage-7.6/local/lib/python/multiprocessing/pool.py", line 
138, in __init__
[sagelib-7.6] self._setup_queues()
[sagelib-7.6]   File 
"/usr/local/src/sage-7.6/local/lib/python/multiprocessing/pool.py", line 
233, in _setup_queues
[sagelib-7.6] from .queues import SimpleQueue
[sagelib-7.6]   File 
"/usr/local/src/sage-7.6/local/lib/python/multiprocessing/queues.py", line 
48, in 
[sagelib-7.6] from .synchronize import Lock, BoundedSemaphore, 
Semaphore, Condition
[sagelib-7.6]   File 
"/usr/local/src/sage-7.6/local/lib/python/multiprocessing/synchronize.py", 
line 59, in 
[sagelib-7.6] " function, see issue 3770.")
[sagelib-7.6] ImportError: This platform lacks a functioning sem_open 
implementation, therefore, the required synchronization primitives needed 
will not function, see issue 3770.
[sagelib-7.6] 

[sagelib-7.6] Error building the Sage library
[sagelib-7.6] 

[sagelib-7.6] Please email sage-devel 
(http://groups.google.com/group/sage-devel)
[sagelib-7.6] explaining the problem and including the relevant part of the 
log file
[sagelib-7.6]   /usr/local/src/sage-7.6/logs/pkgs/sagelib-7.6.log
[sagelib-7.6] Describe your computer, operating system, etc.
[sagelib-7.6] 

[sagelib-7.6] make[3]: *** [Makefile:34: sage] Error 1
[sagelib-7.6] make[3]: Leaving directory '/usr/local/src/sage-7.6/src'
[sagelib-7.6] 
[sagelib-7.6] real  0m2.641s
[sagelib-7.6] user  0m2.474s
[sagelib-7.6] sys   0m0.150s
make[2]: *** [Makefile:1040: sagelib] Error 2
make[2]: Leaving directory '/usr/local/src/sage-7.6/build/make'
make[1]: *** [Makefile:912: all] Error 2
make[1]: Leaving directory '/usr/local/src/sage-7.6/build/make'

real0m3.087s
user0m2.863s
sys 0m0.192s
***
Error building Sage.

The following package(s) may have failed to build (not necessarily
during this run of 'make all'):

* package: sagelib-7.6
  log file: /usr/local/src/sage-7.6/logs/pkgs/sagelib-7.6.log
  build directory: 
/usr/local/src/sage-7.6/local/var/tmp/sage/build/sagelib-7.6

The build directory may contain configuration files and other potentially
helpful information. WARNING: if you now run 'make' again, the build
directory will, by default, be deleted. Set the environment variable
SAGE_KEEP_BUILT_SPKGS to 'yes' to prevent this.
-


seems my semaphores works ok
(read https://groups.google.com/forum/#!topic/sage-devel/uPqvQQ9GzNE)

bash-4.4$ mount | grep shm
tmpfs on /run/shm type tmpfs (rw,nosuid,nodev)

bash-4.4$ cat sem.c