title: Installing qiskit-aer through pip fails
body: <p>I'm trying to install qiskit on Win10.
  I typed in my admin cmd :
  <code>pip install qiskit</code></p>
  <p>It goes just fine for terra, ignis, and aqua.
  However, I have a C compiler problem when installing aer.
  Here's the error message :</p>
  <pre><code>Microsoft Windows [version 10.0.18363.959]
  (c) 2019 Microsoft Corporation. Tous droits réservés.
  
  C:\WINDOWS\system32&gt;pip install qiskit
  Processing c:\users\bohro\appdata\local\pip\cache\wheels\4d\00\27\1b79b2da1898a0d95508661eb1922c6d44be088f2719708a98\qiskit-0.19.6-py3-none-any.whl
  Requirement already satisfied: qiskit-ignis==0.3.3 in c:\program files (x86)\python\python36-32\lib\site-packages (from qiskit) (0.3.3)
  Requirement already satisfied: qiskit-ibmq-provider==0.7.2 in c:\program files (x86)\python\python36-32\lib\site-packages (from qiskit) (0.7.2)
  Requirement already satisfied: qiskit-aqua==0.7.3 in c:\program files (x86)\python\python36-32\lib\site-packages (from qiskit) (0.7.3)
  Requirement already satisfied: qiskit-terra==0.14.2 in c:\program files (x86)\python\python36-32\lib\site-packages (from qiskit) (0.14.2)
  Collecting qiskit-aer==0.5.2
    Using cached qiskit-aer-0.5.2.tar.gz (10.3 MB)
  Requirement already satisfied: scipy!=0.19.1,&gt;=0.19 in c:\program files (x86)\python\python36-32\lib\site-packages (from qiskit-ignis==0.3.3-&gt;qiskit) (1.5.2)
  Requirement already satisfied: setuptools&gt;=40.1.0 in c:\program files (x86)\python\python36-32\lib\site-packages (from qiskit-ignis==0.3.3-&gt;qiskit) (49.2.1)
  Requirement already satisfied: scikit-learn&gt;=0.17 in c:\program files (x86)\python\python36-32\lib\site-packages (from qiskit-ignis==0.3.3-&gt;qiskit) (0.23.2)
  Requirement already satisfied: numpy&gt;=1.13 in c:\program files (x86)\python\python36-32\lib\site-packages (from qiskit-ignis==0.3.3-&gt;qiskit) (1.19.1)
  Requirement already satisfied: requests&gt;=2.19 in c:\program files (x86)\python\python36-32\lib\site-packages (from qiskit-ibmq-provider==0.7.2-&gt;qiskit) (2.22.0)
  Requirement already satisfied: nest-asyncio!=1.1.0,&gt;=1.0.0 in c:\program files (x86)\python\python36-32\lib\site-packages (from qiskit-ibmq-provider==0.7.2-&gt;qiskit) (1.4.0)
  Requirement already satisfied: python-dateutil&gt;=2.8.0 in c:\program files (x86)\python\python36-32\lib\site-packages (from qiskit-ibmq-provider==0.7.2-&gt;qiskit) (2.8.1)
  Requirement already satisfied: urllib3&gt;=1.21.1 in c:\program files (x86)\python\python36-32\lib\site-packages (from qiskit-ibmq-provider==0.7.2-&gt;qiskit) (1.25.7)
  Requirement already satisfied: requests-ntlm&gt;=1.1.0 in c:\program files (x86)\python\python36-32\lib\site-packages (from qiskit-ibmq-provider==0.7.2-&gt;qiskit) (1.1.0)
  Requirement already satisfied: websockets&lt;8,&gt;=7 in c:\program files (x86)\python\python36-32\lib\site-packages (from qiskit-ibmq-provider==0.7.2-&gt;qiskit) (7.0)
  Requirement already satisfied: fastdtw in c:\program files (x86)\python\python36-32\lib\site-packages (from qiskit-aqua==0.7.3-&gt;qiskit) (0.3.4)
  Requirement already satisfied: h5py in c:\program files (x86)\python\python36-32\lib\site-packages (from qiskit-aqua==0.7.3-&gt;qiskit) (2.10.0)
  Requirement already satisfied: networkx&gt;=2.2 in c:\program files (x86)\python\python36-32\lib\site-packages (from qiskit-aqua==0.7.3-&gt;qiskit) (2.4)
  Requirement already satisfied: sympy&gt;=1.3 in c:\program files (x86)\python\python36-32\lib\site-packages (from qiskit-aqua==0.7.3-&gt;qiskit) (1.5.1)
  Requirement already satisfied: quandl in c:\program files (x86)\python\python36-32\lib\site-packages (from qiskit-aqua==0.7.3-&gt;qiskit) (3.5.2)
  Requirement already satisfied: docplex in c:\program files (x86)\python\python36-32\lib\site-packages (from qiskit-aqua==0.7.3-&gt;qiskit) (2.15.194)
  Requirement already satisfied: psutil&gt;=5 in c:\program files (x86)\python\python36-32\lib\site-packages (from qiskit-aqua==0.7.3-&gt;qiskit) (5.7.2)
  Requirement already satisfied: dlx in c:\program files (x86)\python\python36-32\lib\site-packages (from qiskit-aqua==0.7.3-&gt;qiskit) (1.0.4)
  Requirement already satisfied: dill&gt;=0.3 in c:\program files (x86)\python\python36-32\lib\site-packages (from qiskit-terra==0.14.2-&gt;qiskit) (0.3.2)
  Requirement already satisfied: ply&gt;=3.10 in c:\program files (x86)\python\python36-32\lib\site-packages (from qiskit-terra==0.14.2-&gt;qiskit) (3.11)
  Requirement already satisfied: marshmallow&lt;4,&gt;=3 in c:\program files (x86)\python\python36-32\lib\site-packages (from qiskit-terra==0.14.2-&gt;qiskit) (3.7.1)
  Requirement already satisfied: retworkx&gt;=0.3.2 in c:\program files (x86)\python\python36-32\lib\site-packages (from qiskit-terra==0.14.2-&gt;qiskit) (0.4.0)
  Requirement already satisfied: marshmallow-polyfield&lt;6,&gt;=5.7 in c:\program files (x86)\python\python36-32\lib\site-packages (from qiskit-terra==0.14.2-&gt;qiskit) (5.9)
  Requirement already satisfied: jsonschema&gt;=2.6 in c:\program files (x86)\python\python36-32\lib\site-packages (from qiskit-terra==0.14.2-&gt;qiskit) (2.6.0)
  Requirement already satisfied: fastjsonschema&gt;=2.10 in c:\program files (x86)\python\python36-32\lib\site-packages (from qiskit-terra==0.14.2-&gt;qiskit) (2.14.4)
  Requirement already satisfied: python-constraint&gt;=1.4 in c:\program files (x86)\python\python36-32\lib\site-packages (from qiskit-terra==0.14.2-&gt;qiskit) (1.4.0)
  Requirement already satisfied: cython&gt;=0.27.1 in c:\program files (x86)\python\python36-32\lib\site-packages (from qiskit-aer==0.5.2-&gt;qiskit) (0.29.21)
  Requirement already satisfied: pybind11&gt;=2.4 in c:\program files (x86)\python\python36-32\lib\site-packages (from qiskit-aer==0.5.2-&gt;qiskit) (2.5.0)
  Requirement already satisfied: threadpoolctl&gt;=2.0.0 in c:\program files (x86)\python\python36-32\lib\site-packages (from scikit-learn&gt;=0.17-&gt;qiskit-ignis==0.3.3-&gt;qiskit) (2.1.0)
  Requirement already satisfied: joblib&gt;=0.11 in c:\program files (x86)\python\python36-32\lib\site-packages (from scikit-learn&gt;=0.17-&gt;qiskit-ignis==0.3.3-&gt;qiskit) (0.16.0)
  Requirement already satisfied: chardet&lt;3.1.0,&gt;=3.0.2 in c:\program files (x86)\python\python36-32\lib\site-packages (from requests&gt;=2.19-&gt;qiskit-ibmq-provider==0.7.2-&gt;qiskit) (3.0.4)
  Requirement already satisfied: idna&lt;2.9,&gt;=2.5 in c:\program files (x86)\python\python36-32\lib\site-packages (from requests&gt;=2.19-&gt;qiskit-ibmq-provider==0.7.2-&gt;qiskit) (2.8)
  Requirement already satisfied: certifi&gt;=2017.4.17 in c:\program files (x86)\python\python36-32\lib\site-packages (from requests&gt;=2.19-&gt;qiskit-ibmq-provider==0.7.2-&gt;qiskit) (2019.11.28)
  Requirement already satisfied: six&gt;=1.5 in c:\program files (x86)\python\python36-32\lib\site-packages (from python-dateutil&gt;=2.8.0-&gt;qiskit-ibmq-provider==0.7.2-&gt;qiskit) (1.10.0)
  Requirement already satisfied: ntlm-auth&gt;=1.0.2 in c:\program files (x86)\python\python36-32\lib\site-packages (from requests-ntlm&gt;=1.1.0-&gt;qiskit-ibmq-provider==0.7.2-&gt;qiskit) (1.5.0)
  Requirement already satisfied: cryptography&gt;=1.3 in c:\program files (x86)\python\python36-32\lib\site-packages (from requests-ntlm&gt;=1.1.0-&gt;qiskit-ibmq-provider==0.7.2-&gt;qiskit) (3.0)
  Requirement already satisfied: decorator&gt;=4.3.0 in c:\program files (x86)\python\python36-32\lib\site-packages (from networkx&gt;=2.2-&gt;qiskit-aqua==0.7.3-&gt;qiskit) (4.4.2)
  Requirement already satisfied: mpmath&gt;=0.19 in c:\program files (x86)\python\python36-32\lib\site-packages (from sympy&gt;=1.3-&gt;qiskit-aqua==0.7.3-&gt;qiskit) (1.1.0)
  Requirement already satisfied: inflection&gt;=0.3.1 in c:\program files (x86)\python\python36-32\lib\site-packages (from quandl-&gt;qiskit-aqua==0.7.3-&gt;qiskit) (0.5.0)
  Requirement already satisfied: pandas&gt;=0.14 in c:\program files (x86)\python\python36-32\lib\site-packages (from quandl-&gt;qiskit-aqua==0.7.3-&gt;qiskit) (0.20.3)
  Requirement already satisfied: more-itertools in c:\program files (x86)\python\python36-32\lib\site-packages (from quandl-&gt;qiskit-aqua==0.7.3-&gt;qiskit) (8.4.0)
  Requirement already satisfied: cffi!=1.11.3,&gt;=1.8 in c:\program files (x86)\python\python36-32\lib\site-packages (from cryptography&gt;=1.3-&gt;requests-ntlm&gt;=1.1.0-&gt;qiskit-ibmq-provider==0.7.2-&gt;qiskit) (1.14.1)
  Requirement already satisfied: pytz&gt;=2011k in c:\program files (x86)\python\python36-32\lib\site-packages (from pandas&gt;=0.14-&gt;quandl-&gt;qiskit-aqua==0.7.3-&gt;qiskit) (2017.2)
  Requirement already satisfied: pycparser in c:\program files (x86)\python\python36-32\lib\site-packages (from cffi!=1.11.3,&gt;=1.8-&gt;cryptography&gt;=1.3-&gt;requests-ntlm&gt;=1.1.0-&gt;qiskit-ibmq-provider==0.7.2-&gt;qiskit) (2.20)
  Building wheels for collected packages: qiskit-aer
    Building wheel for qiskit-aer (setup.py) ... error
    ERROR: Command errored out with exit status 1:
     command: 'c:\program files (x86)\python\python36-32\python.exe' -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '&quot;'&quot;'C:\\Users\\bohro\\AppData\\Local\\Temp\\pip-install-l0zhdsp2\\qiskit-aer\\setup.py'&quot;'&quot;'; __file__='&quot;'&quot;'C:\\Users\\bohro\\AppData\\Local\\Temp\\pip-install-l0zhdsp2\\qiskit-aer\\setup.py'&quot;'&quot;';f=getattr(tokenize, '&quot;'&quot;'open'&quot;'&quot;', open)(__file__);code=f.read().replace('&quot;'&quot;'\r\n'&quot;'&quot;', '&quot;'&quot;'\n'&quot;'&quot;');f.close();exec(compile(code, __file__, '&quot;'&quot;'exec'&quot;'&quot;'))' bdist_wheel -d 'C:\Users\bohro\AppData\Local\Temp\pip-wheel-a8l2_d9y'
         cwd: C:\Users\bohro\AppData\Local\Temp\pip-install-l0zhdsp2\qiskit-aer\
    Complete output (181 lines):
  
  
    --------------------------------------------------------------------------------
    -- Trying &quot;Ninja (Visual Studio 15 2017 v141)&quot; generator
    --------------------------------
    ---------------------------
    ----------------------
    -----------------
    ------------
    -------
    --
    Not searching for unused variables given on the command line.
    -- The C compiler identification is unknown
    -- Detecting C compiler ABI info
    -- Detecting C compiler ABI info - failed
    -- Check for working C compiler: C:/Programs/cygwin64/bin/cc
    -- Check for working C compiler: C:/Programs/cygwin64/bin/cc - broken
    CMake Error at C:/Users/bohro/AppData/Local/Temp/pip-install-l0zhdsp2/qiskit-aer/.eggs/cmake-3.18.0-py3.6-win32.egg/cmake/data/share/cmake-3.18/Modules/CMakeTestCCompiler.cmake:66 (message):
      The C compiler
  
        &quot;C:/Programs/cygwin64/bin/cc&quot;
  
      is not able to compile a simple test program.
  
      It fails with the following output:
  
        Change Dir: C:/Users/bohro/AppData/Local/Temp/pip-install-l0zhdsp2/qiskit-aer/_cmake_test_compile/build/CMakeFiles/CMakeTmp
  
        Run Build Command(s):C:/Users/bohro/Documents/Programs/ninja-win/ninja.exe cmTC_ba073 &amp;&amp; ninja: fatal: CreateProcess: AccÃžs refusÃš.
  
  
  
  
  
  
      CMake will not be able to correctly generate this project.
    Call Stack (most recent call first):
      CMakeLists.txt:3 (ENABLE_LANGUAGE)
  
  
    -- Configuring incomplete, errors occurred!
    See also &quot;C:/Users/bohro/AppData/Local/Temp/pip-install-l0zhdsp2/qiskit-aer/_cmake_test_compile/build/CMakeFiles/CMakeOutput.log&quot;.
    See also &quot;C:/Users/bohro/AppData/Local/Temp/pip-install-l0zhdsp2/qiskit-aer/_cmake_test_compile/build/CMakeFiles/CMakeError.log&quot;.
    --
    -------
    ------------
    -----------------
    ----------------------
    ---------------------------
    --------------------------------
    -- Trying &quot;Ninja (Visual Studio 15 2017 v141)&quot; generator - failure
    --------------------------------------------------------------------------------
  
  
  
    --------------------------------------------------------------------------------
    -- Trying &quot;Visual Studio 15 2017 v141&quot; generator
    --------------------------------
    ---------------------------
    ----------------------
    -----------------
    ------------
    -------
    --
    Not searching for unused variables given on the command line.
    CMake Error at CMakeLists.txt:2 (PROJECT):
      Generator
  
        Visual Studio 15 2017
  
      could not find any instance of Visual Studio.
  
  
  
    -- Configuring incomplete, errors occurred!
    See also &quot;C:/Users/bohro/AppData/Local/Temp/pip-install-l0zhdsp2/qiskit-aer/_cmake_test_compile/build/CMakeFiles/CMakeOutput.log&quot;.
    --
    -------
    ------------
    -----------------
    ----------------------
    ---------------------------
    --------------------------------
    -- Trying &quot;Visual Studio 15 2017 v141&quot; generator - failure
    --------------------------------------------------------------------------------
  
  
  
    --------------------------------------------------------------------------------
    -- Trying &quot;NMake Makefiles (Visual Studio 15 2017 v141)&quot; generator
    --------------------------------
    ---------------------------
    ----------------------
    -----------------
    ------------
    -------
    --
    Not searching for unused variables given on the command line.
    -- The C compiler identification is unknown
    CMake Error at CMakeLists.txt:3 (ENABLE_LANGUAGE):
      The CMAKE_C_COMPILER:
  
        cl
  
      is not a full path and was not found in the PATH.
  
      To use the NMake generator with Visual C++, cmake must be run from a shell
      that can use the compiler cl from the command line.  This environment is
      unable to invoke the cl compiler.  To fix this problem, run cmake from the
      Visual Studio Command Prompt (vcvarsall.bat).
  
      Tell CMake where to find the compiler by setting either the environment
      variable &quot;CC&quot; or the CMake cache entry CMAKE_C_COMPILER to the full path to
      the compiler, or to the compiler name if it is in the PATH.
  
  
    -- Configuring incomplete, errors occurred!
    See also &quot;C:/Users/bohro/AppData/Local/Temp/pip-install-l0zhdsp2/qiskit-aer/_cmake_test_compile/build/CMakeFiles/CMakeOutput.log&quot;.
    See also &quot;C:/Users/bohro/AppData/Local/Temp/pip-install-l0zhdsp2/qiskit-aer/_cmake_test_compile/build/CMakeFiles/CMakeError.log&quot;.
    --
    -------
    ------------
    -----------------
    ----------------------
    ---------------------------
    --------------------------------
    -- Trying &quot;NMake Makefiles (Visual Studio 15 2017 v141)&quot; generator - failure
    --------------------------------------------------------------------------------
  
  
  
    --------------------------------------------------------------------------------
    -- Trying &quot;NMake Makefiles JOM (Visual Studio 15 2017 v141)&quot; generator
    --------------------------------
    ---------------------------
    ----------------------
    -----------------
    ------------
    -------
    --
    Not searching for unused variables given on the command line.
    -- The C compiler identification is unknown
    CMake Error at CMakeLists.txt:3 (ENABLE_LANGUAGE):
      The CMAKE_C_COMPILER:
  
        cl
  
      is not a full path and was not found in the PATH.
  
      To use the JOM generator with Visual C++, cmake must be run from a shell
      that can use the compiler cl from the command line.  This environment is
      unable to invoke the cl compiler.  To fix this problem, run cmake from the
      Visual Studio Command Prompt (vcvarsall.bat).
  
      Tell CMake where to find the compiler by setting either the environment
      variable &quot;CC&quot; or the CMake cache entry CMAKE_C_COMPILER to the full path to
      the compiler, or to the compiler name if it is in the PATH.
  
  
    -- Configuring incomplete, errors occurred!
    See also &quot;C:/Users/bohro/AppData/Local/Temp/pip-install-l0zhdsp2/qiskit-aer/_cmake_test_compile/build/CMakeFiles/CMakeOutput.log&quot;.
    See also &quot;C:/Users/bohro/AppData/Local/Temp/pip-install-l0zhdsp2/qiskit-aer/_cmake_test_compile/build/CMakeFiles/CMakeError.log&quot;.
    --
    -------
    ------------
    -----------------
    ----------------------
    ---------------------------
    --------------------------------
    -- Trying &quot;NMake Makefiles JOM (Visual Studio 15 2017 v141)&quot; generator - failure
    --------------------------------------------------------------------------------
  
    ********************************************************************************
    scikit-build could not get a working generator for your system. Aborting build.
  
    Building windows wheels for Python 3.6 requires Microsoft Visual Studio 2017.
    Get it with &quot;Visual Studio 2017&quot;:
  
      https://visualstudio.microsoft.com/vs/
  
    ********************************************************************************
    ----------------------------------------
    ERROR: Failed building wheel for qiskit-aer
    Running setup.py clean for qiskit-aer
  Failed to build qiskit-aer
  DEPRECATION: Could not build wheels for qiskit-aer which do not use PEP 517. pip will fall back to legacy 'setup.py install' for these. pip 21.0 will remove support for this functionality. A possible replacement is to fix the wheel build issue reported above. You can find discussion regarding this at https://github.com/pypa/pip/issues/8368.
  Installing collected packages: qiskit-aer, qiskit
      Running setup.py install for qiskit-aer ... error
      ERROR: Command errored out with exit status 1:
       command: 'c:\program files (x86)\python\python36-32\python.exe' -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '&quot;'&quot;'C:\\Users\\bohro\\AppData\\Local\\Temp\\pip-install-l0zhdsp2\\qiskit-aer\\setup.py'&quot;'&quot;'; __file__='&quot;'&quot;'C:\\Users\\bohro\\AppData\\Local\\Temp\\pip-install-l0zhdsp2\\qiskit-aer\\setup.py'&quot;'&quot;';f=getattr(tokenize, '&quot;'&quot;'open'&quot;'&quot;', open)(__file__);code=f.read().replace('&quot;'&quot;'\r\n'&quot;'&quot;', '&quot;'&quot;'\n'&quot;'&quot;');f.close();exec(compile(code, __file__, '&quot;'&quot;'exec'&quot;'&quot;'))' install --record 'C:\Users\bohro\AppData\Local\Temp\pip-record-di0j_g0q\install-record.txt' --single-version-externally-managed --compile --install-headers 'c:\program files (x86)\python\python36-32\Include\qiskit-aer'
           cwd: C:\Users\bohro\AppData\Local\Temp\pip-install-l0zhdsp2\qiskit-aer\
      Complete output (181 lines):
  
  
      --------------------------------------------------------------------------------
      -- Trying &quot;Ninja (Visual Studio 15 2017 v141)&quot; generator
      --------------------------------
      ---------------------------
      ----------------------
      -----------------
      ------------
      -------
      --
      Not searching for unused variables given on the command line.
      -- The C compiler identification is unknown
      -- Detecting C compiler ABI info
      -- Detecting C compiler ABI info - failed
      -- Check for working C compiler: C:/Programs/cygwin64/bin/cc
      -- Check for working C compiler: C:/Programs/cygwin64/bin/cc - broken
      CMake Error at C:/Users/bohro/AppData/Local/Temp/pip-install-l0zhdsp2/qiskit-aer/.eggs/cmake-3.18.0-py3.6-win32.egg/cmake/data/share/cmake-3.18/Modules/CMakeTestCCompiler.cmake:66 (message):
        The C compiler
  
          &quot;C:/Programs/cygwin64/bin/cc&quot;
  
        is not able to compile a simple test program.
  
        It fails with the following output:
  
          Change Dir: C:/Users/bohro/AppData/Local/Temp/pip-install-l0zhdsp2/qiskit-aer/_cmake_test_compile/build/CMakeFiles/CMakeTmp
  
          Run Build Command(s):C:/Users/bohro/Documents/Programs/ninja-win/ninja.exe cmTC_762f9 &amp;&amp; ninja: fatal: CreateProcess: AccÃžs refusÃš.
  
  
  
  
  
  
        CMake will not be able to correctly generate this project.
      Call Stack (most recent call first):
        CMakeLists.txt:3 (ENABLE_LANGUAGE)
  
  
      -- Configuring incomplete, errors occurred!
      See also &quot;C:/Users/bohro/AppData/Local/Temp/pip-install-l0zhdsp2/qiskit-aer/_cmake_test_compile/build/CMakeFiles/CMakeOutput.log&quot;.
      See also &quot;C:/Users/bohro/AppData/Local/Temp/pip-install-l0zhdsp2/qiskit-aer/_cmake_test_compile/build/CMakeFiles/CMakeError.log&quot;.
      --
      -------
      ------------
      -----------------
      ----------------------
      ---------------------------
      --------------------------------
      -- Trying &quot;Ninja (Visual Studio 15 2017 v141)&quot; generator - failure
      --------------------------------------------------------------------------------
  
  
  
      --------------------------------------------------------------------------------
      -- Trying &quot;Visual Studio 15 2017 v141&quot; generator
      --------------------------------
      ---------------------------
      ----------------------
      -----------------
      ------------
      -------
      --
      Not searching for unused variables given on the command line.
      CMake Error at CMakeLists.txt:2 (PROJECT):
        Generator
  
          Visual Studio 15 2017
  
        could not find any instance of Visual Studio.
  
  
  
      -- Configuring incomplete, errors occurred!
      See also &quot;C:/Users/bohro/AppData/Local/Temp/pip-install-l0zhdsp2/qiskit-aer/_cmake_test_compile/build/CMakeFiles/CMakeOutput.log&quot;.
      --
      -------
      ------------
      -----------------
      ----------------------
      ---------------------------
      --------------------------------
      -- Trying &quot;Visual Studio 15 2017 v141&quot; generator - failure
      --------------------------------------------------------------------------------
  
  
  
      --------------------------------------------------------------------------------
      -- Trying &quot;NMake Makefiles (Visual Studio 15 2017 v141)&quot; generator
      --------------------------------
      ---------------------------
      ----------------------
      -----------------
      ------------
      -------
      --
      Not searching for unused variables given on the command line.
      -- The C compiler identification is unknown
      CMake Error at CMakeLists.txt:3 (ENABLE_LANGUAGE):
        The CMAKE_C_COMPILER:
  
          cl
  
        is not a full path and was not found in the PATH.
  
        To use the NMake generator with Visual C++, cmake must be run from a shell
        that can use the compiler cl from the command line.  This environment is
        unable to invoke the cl compiler.  To fix this problem, run cmake from the
        Visual Studio Command Prompt (vcvarsall.bat).
  
        Tell CMake where to find the compiler by setting either the environment
        variable &quot;CC&quot; or the CMake cache entry CMAKE_C_COMPILER to the full path to
        the compiler, or to the compiler name if it is in the PATH.
  
  
      -- Configuring incomplete, errors occurred!
      See also &quot;C:/Users/bohro/AppData/Local/Temp/pip-install-l0zhdsp2/qiskit-aer/_cmake_test_compile/build/CMakeFiles/CMakeOutput.log&quot;.
      See also &quot;C:/Users/bohro/AppData/Local/Temp/pip-install-l0zhdsp2/qiskit-aer/_cmake_test_compile/build/CMakeFiles/CMakeError.log&quot;.
      --
      -------
      ------------
      -----------------
      ----------------------
      ---------------------------
      --------------------------------
      -- Trying &quot;NMake Makefiles (Visual Studio 15 2017 v141)&quot; generator - failure
      --------------------------------------------------------------------------------
  
  
  
      --------------------------------------------------------------------------------
      -- Trying &quot;NMake Makefiles JOM (Visual Studio 15 2017 v141)&quot; generator
      --------------------------------
      ---------------------------
      ----------------------
      -----------------
      ------------
      -------
      --
      Not searching for unused variables given on the command line.
      -- The C compiler identification is unknown
      CMake Error at CMakeLists.txt:3 (ENABLE_LANGUAGE):
        The CMAKE_C_COMPILER:
  
          cl
  
        is not a full path and was not found in the PATH.
  
        To use the JOM generator with Visual C++, cmake must be run from a shell
        that can use the compiler cl from the command line.  This environment is
        unable to invoke the cl compiler.  To fix this problem, run cmake from the
        Visual Studio Command Prompt (vcvarsall.bat).
  
        Tell CMake where to find the compiler by setting either the environment
        variable &quot;CC&quot; or the CMake cache entry CMAKE_C_COMPILER to the full path to
        the compiler, or to the compiler name if it is in the PATH.
  
  
      -- Configuring incomplete, errors occurred!
      See also &quot;C:/Users/bohro/AppData/Local/Temp/pip-install-l0zhdsp2/qiskit-aer/_cmake_test_compile/build/CMakeFiles/CMakeOutput.log&quot;.
      See also &quot;C:/Users/bohro/AppData/Local/Temp/pip-install-l0zhdsp2/qiskit-aer/_cmake_test_compile/build/CMakeFiles/CMakeError.log&quot;.
      --
      -------
      ------------
      -----------------
      ----------------------
      ---------------------------
      --------------------------------
      -- Trying &quot;NMake Makefiles JOM (Visual Studio 15 2017 v141)&quot; generator - failure
      --------------------------------------------------------------------------------
  
      ********************************************************************************
      scikit-build could not get a working generator for your system. Aborting build.
  
      Building windows wheels for Python 3.6 requires Microsoft Visual Studio 2017.
      Get it with &quot;Visual Studio 2017&quot;:
  
        https://visualstudio.microsoft.com/vs/
  
      ********************************************************************************
      ----------------------------------------
  ERROR: Command errored out with exit status 1: 'c:\program files (x86)\python\python36-32\python.exe' -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '&quot;'&quot;'C:\\Users\\bohro\\AppData\\Local\\Temp\\pip-install-l0zhdsp2\\qiskit-aer\\setup.py'&quot;'&quot;'; __file__='&quot;'&quot;'C:\\Users\\bohro\\AppData\\Local\\Temp\\pip-install-l0zhdsp2\\qiskit-aer\\setup.py'&quot;'&quot;';f=getattr(tokenize, '&quot;'&quot;'open'&quot;'&quot;', open)(__file__);code=f.read().replace('&quot;'&quot;'\r\n'&quot;'&quot;', '&quot;'&quot;'\n'&quot;'&quot;');f.close();exec(compile(code, __file__, '&quot;'&quot;'exec'&quot;'&quot;'))' install --record 'C:\Users\bohro\AppData\Local\Temp\pip-record-di0j_g0q\install-record.txt' --single-version-externally-managed --compile --install-headers 'c:\program files (x86)\python\python36-32\Include\qiskit-aer' Check the logs for full command output.
  
  C:\WINDOWS\system32&gt;
  
  </code></pre>
  <p>From what I understand, the problem is related to cygwin (which has already caused me much trouble - never using it again, gotta keep it for now because of university projects that require it). I've installed Cmake, i can open cmake-gui.
  But I don't know how to get this compiler to be used by pip.</p>
  <p>Moreover, contrary to what the error message says, I do have Visual Studio...</p>
  <p>Thanks for the help,
  Kal8578</p>