Troubleshooting and Known Issues

1. yt compilation complains with something like: “Error compiling Cython file”

Answer - try running:

pip install -U Cython

2. Python-fsps compilation returns errors along the lines of


compiling Fortran sources
Fortran f77 compiler: /usr/bin/gfortran -Wall -ffixed-form -fno-second-underscore -fPIC -O3 -funroll-loops
Fortran f90 compiler: /usr/bin/gfortran -fPIC -fPIC -O3 -funroll-loops

Try re-compiling with the flag:


2. Python-fsps compilation can’t find ‘f95’

Error (see here):

Could not locate executable f95
error: Command "f95 -fPIC -fPIC -O3 ..." failed with exit status 127

Try setting an alias to gfortran in your .bashrc:

alias f95='gfortran'

If this doesn’t work, create a soft link to the gfortran executable in your path, e.g.:

ln -s /apps/compilers/gcc/6.3.0/bin/gfortran ~/bin/f95

3. When running pd via a SLURM scheduler, you get the error when importing fsps


build/bdist.linux-x86_64/egg/fsps/ in <module>()
ImportError: Your FSPS version does not seem to be under git version control. FSPS is available on github at and should be cloned from there

Comment out the lines in python-fsps/fsps/ surrounding the checking of githashes. (h/t to Ena Choi for uncovering this one).

4. If in powderday you start getting memory errors on the Pool process call that look like this:


calculating the SEDs for  42  bins
Traceback (most recent call last):
File "/ufrc/narayanan/desika.narayanan/pd/", line 139, in <module>
File "/ufrc/narayanan/desika.narayanan/pd/", line 244, in add_binned_seds
  #of star particles that go in every [wz,wa,wm]
File "/ufrc/narayanan/desika.narayanan/pd/", line 225, in allstars_sed_gen
  p = Pool(processes = cfg.par.n_processes)
File "/ufrc/narayanan/desika.narayanan/miniconda2/lib/python2.7/multiprocessing/", line 232, in Pool
  return Pool(processes, initializer, initargs, maxtasksperchild)
File "/ufrc/narayanan/desika.narayanan/miniconda2/lib/python2.7/multiprocessing/", line 159, in __init__
File "/ufrc/narayanan/desika.narayanan/miniconda2/lib/python2.7/multiprocessing/", line 223, in _repopulate_pool
File "/ufrc/narayanan/desika.narayanan/miniconda2/lib/python2.7/multiprocessing/", line 130, in start
  self._popen = Popen(self)
File "/ufrc/narayanan/desika.narayanan/miniconda2/lib/python2.7/multiprocessing/", line 121, in __init__ = os.fork()
OSError: [Errno 12] Cannot allocate memory

Try reducing the number of n_processes in the file

6. errors in powderday

Freezing during and ‘metallicity outside of range’ errors:

Entering multiprocessing for Stellar SED generation
SSP_GEN ERROR: metallicity outside of range          14
SSP_GEN ERROR: metallicity outside of range          15

Some installations have encountered this issue, but its cause has not yet been determined. One potential fix could be using Miniconda instead of Anaconda Python, although this has not been confirmed to be the source of the problem. If something went wrong at any point in the installation process, starting from scratch and doing a fresh installation may also fix the issue.

6. Can’t find “builtins”

During run, we get an error that looks like:

(pd4env) [[email protected] pd_git]$  tests/SKIRT/gizmo_mw_zoom/ parameters_master_401 parameters_model_401
Traceback (most recent call last):
File "/home/desika.narayanan/miniconda3/envs/pd4env/bin/", line 4, in <module>
  __import__('pkg_resources').run_script('powderday==0.1.0', '')
File "/home/desika.narayanan/miniconda3/envs/pd4env/lib/python2.7/site-packages/pkg_resources/", line 666, in run_script
  self.require(requires)[0].run_script(script_name, ns)
File "/home/desika.narayanan/miniconda3/envs/pd4env/lib/python2.7/site-packages/pkg_resources/", line 1469, in run_script
  exec(script_code, namespace, namespace)
File "/home/desika.narayanan/miniconda3/envs/pd4env/lib/python2.7/site-packages/powderday-0.1.0-py2.7.egg/EGG-INFO/scripts/", line 7, in <module>

File "build/bdist.linux-x86_64/egg/powderday/", line 4, in <module>
File "build/bdist.linux-x86_64/egg/powderday/", line 19, in <module>
File "build/bdist.linux-x86_64/egg/powderday/nebular_emission/", line 2, in <module>
File "build/bdist.linux-x86_64/egg/powderd

Try the following::
pip install future