Bug Description
If I install qutip in editable mode, string compilation of coefficients does not work. I am pretty sure that it used to work, but unsure when it stopped working.
I create a new environment as follows:
conda create -n test-env python numpy scipy cython setuptools filelock ipython
conda activate test-env
pip install -e .
Code to Reproduce the Bug
import qutip as qt
qt.QobjEvo([[qt.sigmax(), "4*t"]])
Code Output
[1/1] Cythonizing qtcoeff_a42fab432721dbd96deac9f1ef8bbc.pyx
Error compiling Cython file:
------------------------------------------------------------
...
import numpy as np
import scipy.special as spe
from scipy.special cimport cython_special
cimport cython
from qutip.core.cy.coefficient cimport Coefficient
^
------------------------------------------------------------
qtcoeff_a42fab432721dbd96deac9f1ef8bbc.pyx:8:0: 'qutip/core/cy/coefficient.pxd' not found
Error compiling Cython file:
------------------------------------------------------------
...
import numpy as np
import scipy.special as spe
from scipy.special cimport cython_special
cimport cython
from qutip.core.cy.coefficient cimport Coefficient
^
------------------------------------------------------------
qtcoeff_a42fab432721dbd96deac9f1ef8bbc.pyx:8:0: 'qutip/core/cy/coefficient/Coefficient.pxd' not found
Error compiling Cython file:
------------------------------------------------------------
...
import numpy as np
import scipy.special as spe
from scipy.special cimport cython_special
cimport cython
from qutip.core.cy.coefficient cimport Coefficient
from qutip.core.cy.math cimport erf, zerf
^
------------------------------------------------------------
qtcoeff_a42fab432721dbd96deac9f1ef8bbc.pyx:9:0: 'qutip/core/cy/math.pxd' not found
Error compiling Cython file:
------------------------------------------------------------
...
import numpy as np
import scipy.special as spe
from scipy.special cimport cython_special
cimport cython
from qutip.core.cy.coefficient cimport Coefficient
from qutip.core.cy.math cimport erf, zerf
^
------------------------------------------------------------
qtcoeff_a42fab432721dbd96deac9f1ef8bbc.pyx:9:0: 'qutip/core/cy/math/erf.pxd' not found
Error compiling Cython file:
------------------------------------------------------------
...
import numpy as np
import scipy.special as spe
from scipy.special cimport cython_special
cimport cython
from qutip.core.cy.coefficient cimport Coefficient
from qutip.core.cy.math cimport erf, zerf
^
------------------------------------------------------------
qtcoeff_a42fab432721dbd96deac9f1ef8bbc.pyx:9:0: 'qutip/core/cy/math/zerf.pxd' not found
Error compiling Cython file:
------------------------------------------------------------
...
import scipy.special as spe
from scipy.special cimport cython_special
cimport cython
from qutip.core.cy.coefficient cimport Coefficient
from qutip.core.cy.math cimport erf, zerf
from qutip.core.cy.complex_math cimport *
^
------------------------------------------------------------
qtcoeff_a42fab432721dbd96deac9f1ef8bbc.pyx:10:0: 'qutip/core/cy/complex_math.pxd' not found
Error compiling Cython file:
------------------------------------------------------------
...
from scipy.special cimport cython_special
cimport cython
from qutip.core.cy.coefficient cimport Coefficient
from qutip.core.cy.math cimport erf, zerf
from qutip.core.cy.complex_math cimport *
from qutip.core.data cimport Data
^
------------------------------------------------------------
qtcoeff_a42fab432721dbd96deac9f1ef8bbc.pyx:11:0: 'qutip/core/data.pxd' not found
Error compiling Cython file:
------------------------------------------------------------
...
from scipy.special cimport cython_special
cimport cython
from qutip.core.cy.coefficient cimport Coefficient
from qutip.core.cy.math cimport erf, zerf
from qutip.core.cy.complex_math cimport *
from qutip.core.data cimport Data
^
------------------------------------------------------------
qtcoeff_a42fab432721dbd96deac9f1ef8bbc.pyx:11:0: 'qutip/core/data/Data.pxd' not found
Error compiling Cython file:
------------------------------------------------------------
...
parsed_code = "self._cte_cpl0 * t"
@cython.auto_pickle(True)
cdef class StrCoefficient(Coefficient):
^
------------------------------------------------------------
qtcoeff_a42fab432721dbd96deac9f1ef8bbc.pyx:18:26: First base of 'StrCoefficient' is not an extension type
Error compiling Cython file:
------------------------------------------------------------
...
def __init__(self, base, var, cte, args):
self.codeString = base
self._cte_cpl0 = cte[0]
cpdef Coefficient copy(self):
^
------------------------------------------------------------
qtcoeff_a42fab432721dbd96deac9f1ef8bbc.pyx:32:10: 'Coefficient' is not a type identifier
---------------------------------------------------------------------------
CompileError Traceback (most recent call last)
File ~/qutip/github_master/qutip/core/coefficient.py:619, in compile_code(code, file_name, parsed, c_opt)
611 coeff_file = Extension(
612 file_name,
613 sources=[file_name + ".pyx"],
(...) 617 language='c++'
618 )
--> 619 ext_modules = cythonize(
620 coeff_file, force=True, build_dir=c_opt['build_dir']
621 )
622 setup(ext_modules=ext_modules)
File ~/miniconda3/envs/test-env/lib/python3.14t/site-packages/Cython/Build/Dependencies.py:1150, in cythonize(module_list, exclude, nthreads, aliases, quiet, force, language, exclude_failures, show_all_warnings, **options)
1149 for args in to_compile:
-> 1150 cythonize_one(*args)
1152 if exclude_failures:
File ~/miniconda3/envs/test-env/lib/python3.14t/site-packages/Cython/Build/Dependencies.py:1294, in cythonize_one(pyx_file, c_file, fingerprint, quiet, options, raise_on_failure, embedded_metadata, full_module_name, show_all_warnings, progress, cache)
1293 if raise_on_failure:
-> 1294 raise CompileError(None, pyx_file)
1295 elif os.path.exists(c_file):
CompileError: qtcoeff_a42fab432721dbd96deac9f1ef8bbc.pyx
The above exception was the direct cause of the following exception:
Exception Traceback (most recent call last)
Cell In[3], line 1
----> 1 qt.QobjEvo([[qt.sigmax(), "4*t"]])
File qutip/core/cy/qobjevo.pyx:223, in qutip.core.cy.qobjevo.QobjEvo.__init__()
File qutip/core/cy/qobjevo.pyx:272, in qutip.core.cy.qobjevo.QobjEvo._read_element()
File ~/qutip/github_master/qutip/core/coefficient.py:192, in coefficient(base, tlist, args, args_ctypes, order, compile_opt, function_style, boundary_conditions, **kwargs)
190 for type_ in coefficient_builders:
191 if isinstance(base, type_):
--> 192 return coefficient_builders[type_](base, **kwargs)
194 if callable(base):
195 args = args or {}
File ~/qutip/github_master/qutip/core/coefficient.py:444, in coeff_from_str(base, args, args_ctypes, compile_opt, **_)
441 code = make_cy_code(parsed, variables, constants,
442 raw, compile_opt)
443 try:
--> 444 coeff = compile_code(code, file_name, parsed, compile_opt)
445 except PermissionError:
446 pass
File ~/qutip/github_master/qutip/core/coefficient.py:627, in compile_code(code, file_name, parsed, c_opt)
625 for file in glob.glob(file_name + "*"):
626 os.remove(file)
--> 627 raise Exception("Could not compile") from e
628 finally:
629 sys.argv = oldargs
Exception: Could not compileExpected Behaviour
There is no error.
Your Environment
QuTiP Version: 5.3.0.dev0+f15c8f2
Numpy Version: 2.3.4
Scipy Version: 1.16.2
Cython Version: 3.1.6
Matplotlib Version: None
Python Version: 3.14.0
Number of CPUs: 20
BLAS Info: blas
INTEL MKL Ext: None
Platform Info: Linux (x86_64)
Installation path: /home/paulm/qutip/github_master/qutip
Additional Context
The error is due to cython not finding qutip's pxd files. Cython looks for those in sys.path, and indeed, the installation directory is not in sys.path for me. I can add the path
sys.path.append('/home/paulm/qutip/github_master')and this changes the error into
[1/1] Cythonizing qtcoeff_a42fab432721dbd96deac9f1ef8bbc.pyx
running build_ext
building 'qtcoeff_a42fab432721dbd96deac9f1ef8bbc' extension
g++ -pthread -B /home/paulm/miniconda3/envs/test-env/share/python_compiler_compat -fno-strict-overflow -Wsign-compare -DNDEBUG -O2 -Wall -fPIC -O2 -isystem /home/paulm/miniconda3/envs/test-env/include -fPIC -O2 -isystem /home/paulm/miniconda3/envs/test-env/include -fPIC -I/home/paulm/miniconda3/envs/test-env/lib/python3.14t/site-packages/numpy/_core/include -I/home/paulm/miniconda3/envs/test-env/include/python3.14t -c qtcoeff_a42fab432721dbd96deac9f1ef8bbc.cpp -o build/temp.linux-x86_64-cpython-314t/qtcoeff_a42fab432721dbd96deac9f1ef8bbc.o -w -O3 -funroll-loops
qtcoeff_a42fab432721dbd96deac9f1ef8bbc.cpp:1173:10: fatal error: src/intdtype.h: No such file or directory
1173 | #include "src/intdtype.h"
| ^~~~~~~~~~~~~~~~
compilation terminated.
An exception has occurred, use %tb to see the full traceback.
SystemExit: error: command '/usr/bin/g++' failed with exit code 1
That is, now it fails to find the src/intdtype.h header in qutip/core/data. This directory would need to be included in the include_dirs here, I guess - but now I wonder how it does seemingly find this header file in regular qutip installations.
Bug Description
If I install qutip in editable mode, string compilation of coefficients does not work. I am pretty sure that it used to work, but unsure when it stopped working.
I create a new environment as follows:
conda create -n test-env python numpy scipy cython setuptools filelock ipython conda activate test-env pip install -e .Code to Reproduce the Bug
Code Output
Expected Behaviour
There is no error.
Your Environment
Additional Context
The error is due to cython not finding qutip's
pxdfiles. Cython looks for those insys.path, and indeed, the installation directory is not insys.pathfor me. I can add the pathand this changes the error into
That is, now it fails to find the
src/intdtype.hheader inqutip/core/data. This directory would need to be included in theinclude_dirshere, I guess - but now I wonder how it does seemingly find this header file in regular qutip installations.