Falied install flask under virutalenv on windows - [Error 2] The system cannot find the specified file

Question

I am using python 2.7 on windows window. I can install the flask using pip install, as you can see below:

However, after I created virtualenv, I was mistaken in trying to do the same.

scripts:

$pip install virtualenv $cd /dd: $mkdir test $cd test $virtualenv flaskEnv $cd flaskEnv/Scritps/ $activate $cd ../../ $pip install flask 

log file as below:

 Collecting flask Using cached Flask-0.11.1-py2.py3-none-any.whl Requirement already satisfied (use --upgrade to upgrade): click>=2.0 in c:\projects\flask-react\flsk\lib\site-packages (from flask) Requirement already satisfied (use --upgrade to upgrade): Werkzeug>=0.7 in c:\projects\flask-react\flsk\lib\site-packages (from flask) Collecting Jinja2>=2.4 (from flask) Using cached Jinja2-2.8-py2.py3-none-any.whl Collecting itsdangerous>=0.21 (from flask) Collecting MarkupSafe (from Jinja2>=2.4->flask) Using cached MarkupSafe-0.23.tar.gz Building wheels for collected packages: MarkupSafe Running setup.py bdist_wheel for MarkupSafe: started Running setup.py bdist_wheel for MarkupSafe: finished with status 'error' Complete output from command c:\projects\flask-react\flsk\scripts\python.exe -u -c "import setuptools, tokenize;__file__='c:\\users\\admini~1\\appdata\\local\\temp\\pip-build-3ep417\\MarkupSafe\\setup.py';exec(compile(getattr(tokenize, 'open', open)(__file__).read().replace('\r\n', '\n'), __file__, 'exec'))" bdist_wheel -dc:\users\admini~1\appdata\local\temp\tmp8mkr70pip-wheel- --python-tag cp27: running bdist_wheel running build running build_py creating build creating build\lib.win32-2.7 creating build\lib.win32-2.7\markupsafe copying markupsafe\tests.py -> build\lib.win32-2.7\markupsafe copying markupsafe\_compat.py -> build\lib.win32-2.7\markupsafe copying markupsafe\_constants.py -> build\lib.win32-2.7\markupsafe copying markupsafe\_native.py -> build\lib.win32-2.7\markupsafe copying markupsafe\__init__.py -> build\lib.win32-2.7\markupsafe running egg_info writing MarkupSafe.egg-info\PKG-INFO writing top-level names to MarkupSafe.egg-info\top_level.txt writing dependency_links to MarkupSafe.egg-info\dependency_links.txt warning: manifest_maker: standard file '-c' not found reading manifest file 'MarkupSafe.egg-info\SOURCES.txt' reading manifest template 'MANIFEST.in' writing manifest file 'MarkupSafe.egg-info\SOURCES.txt' copying markupsafe\_speedups.c -> build\lib.win32-2.7\markupsafe running build_ext building 'markupsafe._speedups' extension error: [Error 2] The system cannot find the file specified ---------------------------------------- Running setup.py clean for MarkupSafe Failed to build MarkupSafe Installing collected packages: MarkupSafe, Jinja2, itsdangerous, flask Running setup.py install for MarkupSafe: started Running setup.py install for MarkupSafe: finished with status 'error' Complete output from command c:\projects\flask-react\flsk\scripts\python.exe -u -c "import setuptools, tokenize;__file__='c:\\users\\admini~1\\appdata\\local\\temp\\pip-build-3ep417\\MarkupSafe\\setup.py';exec(compile(getattr(tokenize, 'open', open)(__file__).read().replace('\r\n', '\n'), __file__, 'exec'))" install --record c:\users\admini~1\appdata\local\temp\pip-8v3_ep-record\install-record.txt --single-version-externally-managed --compile --install-headers c:\projects\flask-react\flsk\include\site\python2.7\MarkupSafe: running install running build running build_py creating build creating build\lib.win32-2.7 creating build\lib.win32-2.7\markupsafe copying markupsafe\tests.py -> build\lib.win32-2.7\markupsafe copying markupsafe\_compat.py -> build\lib.win32-2.7\markupsafe copying markupsafe\_constants.py -> build\lib.win32-2.7\markupsafe copying markupsafe\_native.py -> build\lib.win32-2.7\markupsafe copying markupsafe\__init__.py -> build\lib.win32-2.7\markupsafe running egg_info writing MarkupSafe.egg-info\PKG-INFO writing top-level names to MarkupSafe.egg-info\top_level.txt writing dependency_links to MarkupSafe.egg-info\dependency_links.txt warning: manifest_maker: standard file '-c' not found reading manifest file 'MarkupSafe.egg-info\SOURCES.txt' reading manifest template 'MANIFEST.in' writing manifest file 'MarkupSafe.egg-info\SOURCES.txt' copying markupsafe\_speedups.c -> build\lib.win32-2.7\markupsafe running build_ext building 'markupsafe._speedups' extension error: [Error 2] The system cannot find the file specified 

Does the error message say something? thanks

Answer 1

This issue seems to be related to the version of setuptools installed in your virtualenv. Switching to an earlier version fixed this for me.

From your virtualenv:

 pip install setuptools==21.2.1 pip install flask 

Answer 2

I had this problem yesterday. I resolved it by downloading the MarkupSafe wheel and installing using pip. The problem was over my head. I think something about compiler flags to suppress an error while creating an acceleration file.

1) Download the wheel from the link above.

2) On Windows, open the command window in the same directory as the wheel.

3) run "pip Install"

Answer 3

Installation.py MarkupSafe for Win7 is installed on my system where there is no C compiler (I keep a separate VM for VC ++ to work). I did this to make it work:

 pip download MarkupSafe mkdir temp open MarkupSafe-0.23.tar.gz with 7-zip, extract all to temp cd temp edit setup.py line 119 to read: if 0: #not (is_pypy or is_jython): python setup.py install 

I did not try to debug setup.py to work correctly. I just wanted to try Flask, because it should be easy and easy to learn, and white papers say it installs on Windows. Maybe I should go back to Perl ...

Unlike another poster, the global pipup installation of MarkupSafe didn't work for me either.

These links have other views / ideas on the issue: https://github.com/pallets/markupsafe/issues/26 https://github.com/babun/babun/issues/315

Answer 4

OK. I understand it. I don’t think there is anything wrong with the way I install the jar, as I mentioned in my question, I can install it globally (without starting in virtualenv). the MarkupSafe package has an extension that is implemented using c, and I don’t have the sdk window installed on my local machine, so when ve_build_ext starts up, **** it always fails **

the difference is the absence (is_pypy or is_jython), it gives the warning that I received when installing on a global scale; it crashes, however, when working under virtual. Therefore, I am sure that hasattr (sys, 'pypy_version_info') returns true when working under a virtual file.

Does anyone have an idea that "hasattr (sys," pypy_version_info ") means"

 # fail safe compilation shamelessly stolen from the simplejson # setup.py file. Original author: Bob Ippolito is_jython = 'java' in sys.platform is_pypy = hasattr(sys, 'pypy_version_info') def run_setup(with_binary): ext = Extension('markupsafe._speedups', ['markupsafe/_speedups.c']) ext_modules = [ext] if with_binary else [] def try_building_extension(): try: run_setup(True) except BuildFailed: LINE = '=' * 74 BUILD_EXT_WARNING = 'WARNING: The C extension could not be ' \ 'compiled, speedups are not enabled.' echo(LINE) echo(BUILD_EXT_WARNING) echo('Failure information, if any, is above.') echo('Retrying the build without the C extension now.') echo() run_setup(False) echo(LINE) echo(BUILD_EXT_WARNING) echo('Plain-Python installation succeeded.') echo(LINE) 

if not (is_pypy or is_jython): try_building_extension () also: run_setup (False)

Answer 5

I had this problem today, and I was able to solve it by manually installing MarkupSafe from wheel , as suggested by Lincoln above. You can download the corresponding file here . There were several available. I don’t know what the difference is between them, but the only one that would even install on Windows 10 was MarkupSafe-0.23-cp27-none-win32.whl . After downloading it, I copied it to a directory that I created using virtualenv (not sure if this is necessary, but what I did) and installed it using pip:

 C:\flask-test\venv>pip install MarkupSafe-0.23-cp27-none-win32.whl 

from this directory. After that, I returned to the main directory and checked

 C:\flask-test\venv>cd .. C:\flask-test>pip install Flask 

and it worked fine.