# Pystan windows error in conda

**URL:** <https://discourse.mc-stan.org/t/pystan-windows-error-in-conda/28023>\
**Category:** PyStan\
**Created:** [June 30, 2022, 1:23am UTC](https://discourse.mc-stan.org/t/pystan-windows-error-in-conda/28023 "2022-06-30T01:23:36Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![amaan784](https://avatars.discourse-cdn.com/v4/letter/a/48db29/32.png) [@amaan784](https://discourse.mc-stan.org/u/amaan784)\
**Post date:** [June 30, 2022, 1:23am UTC](https://discourse.mc-stan.org/t/pystan-windows-error-in-conda/28023/1 "2022-06-30T01:23:36Z")

</div>

**When I run the trial code mentioned here**  
**[PyStan on Windows — PyStan 2.19.1.1 documentation](https://pystan2.readthedocs.io/en/latest/windows.html)**

```no-highlight
import pystan
model_code = 'parameters {real y;} model {y ~ normal(0,1);}'
model = pystan.StanModel(model_code=model_code)

```

**I get this error-**  
“”"  
INFO:pystan:COMPILING THE C++ CODE FOR MODEL anon\_model\_5944b02c79788fa0db5b3a93728ca2bf NOW.  
WARNING:pystan:MSVC compiler is not supported  
Traceback (most recent call last):  
File “”, line 1, in   
File “C:\ProgramData\Anaconda3\envs\stan\_env\lib\site-packages\pystan\model.py”, line 378, in **init**  
build\_extension.run()  
File “C:\ProgramData\Anaconda3\envs\stan\_env\lib\site-packages\setuptools\_distutils\command\build\_ext.py”, line 339, in run  
self.build\_extensions()  
File “C:\ProgramData\Anaconda3\envs\stan\_env\lib\site-packages\setuptools\_distutils\command\build\_ext.py”, line 448, in build\_extensions  
self.\_build\_extensions\_serial()  
File “C:\ProgramData\Anaconda3\envs\stan\_env\lib\site-packages\setuptools\_distutils\command\build\_ext.py”, line 473, in \_build\_extensions\_serial  
self.build\_extension(ext)  
File “C:\ProgramData\Anaconda3\envs\stan\_env\lib\site-packages\setuptools\_distutils\command\build\_ext.py”, line 528, in build\_extension  
objects = self.compiler.compile(sources,  
File “C:\ProgramData\Anaconda3\envs\stan\_env\lib\site-packages\setuptools\_distutils\_msvccompiler.py”, line 327, in compile  
self.initialize()  
File “C:\ProgramData\Anaconda3\envs\stan\_env\lib\site-packages\setuptools\_distutils\_msvccompiler.py”, line 224, in initialize  
vc\_env = \_get\_vc\_env(plat\_spec)  
File “C:\ProgramData\Anaconda3\envs\stan\_env\lib\site-packages\setuptools\msvc.py”, line 316, in msvc14\_get\_vc\_env  
return \_msvc14\_get\_vc\_env(plat\_spec)  
File “C:\ProgramData\Anaconda3\envs\stan\_env\lib\site-packages\setuptools\msvc.py”, line 270, in \_msvc14\_get\_vc\_env  
raise distutils.errors.DistutilsPlatformError(  
distutils.errors.DistutilsPlatformError: Microsoft Visual C++ 14.0 or greater is required. Get it with “Microsoft C++ Build Tools”: [Microsoft C++ Build Tools - Visual Studio](https://visualstudio.microsoft.com/visual-cpp-build-tools/)

> > > model = pystan.StanModel(model\_code=model\_code)  
> > > INFO:pystan:COMPILING THE C++ CODE FOR MODEL anon\_model\_5944b02c79788fa0db5b3a93728ca2bf NOW.  
> > > Traceback (most recent call last):  
> > > File “C:\ProgramData\Anaconda3\envs\stan\_env\lib\site-packages\setuptools\_distutils\unixccompiler.py”, line 249, in link  
> > > self.spawn(linker + ld\_args)  
> > > File “C:\ProgramData\Anaconda3\envs\stan\_env\lib\site-packages\setuptools\_distutils\ccompiler.py”, line 917, in spawn  
> > > spawn(cmd, dry\_run=self.dry\_run, \*\*kwargs)  
> > > File “C:\ProgramData\Anaconda3\envs\stan\_env\lib\site-packages\setuptools\_distutils\spawn.py”, line 68, in spawn  
> > > raise DistutilsExecError(  
> > > distutils.errors.DistutilsExecError: command ‘C:\ProgramData\Anaconda3\envs\stan\_env\Library\mingw-w64\bin\g++.exe’ failed with exit code 1

During handling of the above exception, another exception occurred:

Traceback (most recent call last):  
File “”, line 1, in   
File “C:\ProgramData\Anaconda3\envs\stan\_env\lib\site-packages\pystan\model.py”, line 378, in **init**  
build\_extension.run()  
File “C:\ProgramData\Anaconda3\envs\stan\_env\lib\site-packages\setuptools\_distutils\command\build\_ext.py”, line 339, in run  
self.build\_extensions()  
File “C:\ProgramData\Anaconda3\envs\stan\_env\lib\site-packages\setuptools\_distutils\command\build\_ext.py”, line 448, in build\_extensions  
self.\_build\_extensions\_serial()  
File “C:\ProgramData\Anaconda3\envs\stan\_env\lib\site-packages\setuptools\_distutils\command\build\_ext.py”, line 473, in \_build\_extensions\_serial  
self.build\_extension(ext)  
File “C:\ProgramData\Anaconda3\envs\stan\_env\lib\site-packages\setuptools\_distutils\command\build\_ext.py”, line 550, in build\_extension  
self.compiler.link\_shared\_object(  
File “C:\ProgramData\Anaconda3\envs\stan\_env\lib\site-packages\setuptools\_distutils\ccompiler.py”, line 713, in link\_shared\_object  
self.link(CCompiler.SHARED\_OBJECT, objects,  
File “C:\ProgramData\Anaconda3\envs\stan\_env\lib\site-packages\setuptools\_distutils\cygwinccompiler.py”, line 232, in link  
UnixCCompiler.link(self, target\_desc, objects, output\_filename,  
File “C:\ProgramData\Anaconda3\envs\stan\_env\lib\site-packages\setuptools\_distutils\unixccompiler.py”, line 251, in link  
raise LinkError(msg)  
distutils.errors.LinkError: command ‘C:\ProgramData\Anaconda3\envs\stan\_env\Library\mingw-w64\bin\g++.exe’ failed with exit code 1  
“”"

\*\*\* Operating System = Windows (using condas)\*\*  
\*\*\* Python Version = Python 3.9.12\*\*  
\*\*\* PyStan Version = 2.19.1.1\*\*

**Please help me out.**  
**Thanks**

---

<div class="post-metadata">

**Author:** ![mitzimorris](https://yyz2.discourse-cdn.com/flex030/user_avatar/discourse.mc-stan.org/mitzimorris/32/29_2.png) [@mitzimorris](https://discourse.mc-stan.org/u/mitzimorris)\
**Post date:** [July 1, 2022, 9:20pm UTC](https://discourse.mc-stan.org/t/pystan-windows-error-in-conda/28023/2 "2022-07-01T21:20:13Z")

</div>

PyStan doesn’t always work on Windows - [Frequently Asked Questions — pystan 3.4.0 documentation](https://pystan.readthedocs.io/en/latest/faq.html#is-windows-supported)

since you’re using conda, I recommend installing CmdStanPy from conda-forge - [Installation — CmdStanPy 1.0.4 documentation](https://mc-stan.org/cmdstanpy/installation.html#conda-install-cmdstanpy-cmdstan-c-toolchain)

---

<div class="post-metadata">

**Author:** ![ahartikainen](https://yyz2.discourse-cdn.com/flex030/user_avatar/discourse.mc-stan.org/ahartikainen/32/321_2.png) [@ahartikainen](https://discourse.mc-stan.org/u/ahartikainen)\
**Post date:** [July 1, 2022, 10:04pm UTC](https://discourse.mc-stan.org/t/pystan-windows-error-in-conda/28023/3 "2022-07-01T22:04:45Z")

</div>

Your installation can not find gcc (mingw-w64).

Why do you use pystan 2?