MAINT allow to set environment variable at install

readme.md

@@ -48,3 +48,13 @@ The output generated by the above example should look like the following:
 - Cython (only for building and installing, not for everyday use)
 - Pillow (friendly fork of PIL, used here for file I/O with the example and during unit tests)
 - CharLS (source included as subfolder)
+
+## Installing
+
+Under Linux, you need to set the environment variable `MSCV` to be able to install:
+
+```
+export MSCV=False
+pip install .
+```
+

setup.py

@@ -1,11 +1,9 @@
-
-
-import numpy as np
+import os
 import setuptools
-
 from setuptools import setup, find_packages
 from setuptools.extension import Extension
 
+import numpy as np
 from Cython.Distutils import build_ext
 
 # Cython extension.
@@ -20,8 +18,11 @@
 
 extra_link_args = []
 
-flag_MSVC = True  # Set this flag to True if using Visual Studio.
-if flag_MSVC:
+if 'MSCV' in os.environ and os.environ['MSCV'] == 'False':
+    flag_MSCV = False
+else:
+    flag_MSCV = True
+if flag_MSCV:
     extra_compile_args = ['/EHsc']
 else:
     extra_compile_args = []