rework setup.py

Checks whether SCIP is installed in place.
Also checks whether SCIP was build with make.
If this is the case (i.e., libscipsolver.so is used),
turn off config headers.
Default is not to use this, so all other installations
should work as before.

setup.py

@@ -4,28 +4,29 @@
 # look for environment variable that specifies path to SCIP
 scipoptdir = os.environ.get('SCIPOPTDIR', '').strip('"')
 
-# now check whether SCIP is installed on the system or whether a source code directory has been specified
-if os.path.exists(os.path.join(scipoptdir, 'include')):
-    includedir = os.path.abspath(os.path.join(scipoptdir, 'include'))
+# determine include directory
+if os.path.exists(os.path.join(scipoptdir, 'src')):
+    # SCIP seems to be installed in place
+    includedir = os.path.abspath(os.path.join(scipoptdir, 'src'))
 else:
-    if os.path.exists(os.path.join(scipoptdir, 'src')):
-        includedir = os.path.abspath(os.path.join(scipoptdir, 'src'))
-    else:
-        print('Neither directory \'src\' nor \'include\' exists in the path <%s>' % scipoptdir)
-        quit(1)
+    # assume that SCIP is installed on the system
+    includedir = os.path.abspath(os.path.join(scipoptdir, 'include'))
+
+print('Using include path <%s>.' % includedir)
 
 # determine library
-libdir = os.path.abspath(os.path.join(scipoptdir, 'lib'))
-libname = 'scip'
-if (not os.path.exists(os.path.join(libdir, 'libscip.so'))) and (not os.path.exists('/usr/lib/libscip.so')):
-    if os.path.exists(os.path.join(libdir, 'shared/libscipsolver.so')):
-        print('SCIP library <%s> does not exist.\nUsing <%s> instead.' % (os.path.join(libdir, 'libscip.so'), os.path.join(libdir, 'shared/libscipsolver.so')))
-        libdir = os.path.abspath(os.path.join(scipoptdir, 'lib/shared'))
-        libname = 'scipsolver'
-    else:
-        print('SCIP library does not exist - tried <lib/libscip.so> and <lib/shared/libscipsolver.so>.')
-        quit(1)
+if os.path.exists(os.path.join(scipoptdir, 'lib/shared/libscipsolver.so')):
+    # SCIP seems to be created with make
+    libdir = os.path.abspath(os.path.join(scipoptdir, 'lib/shared'))
+    libname = 'scipsolver'
+    withmake = 1
+else:
+    # assume that SCIP is installed on the system
+    libdir = os.path.abspath(os.path.join(scipoptdir, 'lib'))
+    libname = 'scip'
+    withmake = 0
 
+print('Using SCIP library <%s> at <%s>.' % (libname,libdir))
 
 cythonize = True
 
@@ -61,7 +62,8 @@
     sys.argv.remove("--debug")
 
 # avoid errors if SCIP is build with make:
-extra_compile_args.append('-DNO_CONFIG_HEADER')
+if withmake == 1:
+    extra_compile_args.append('-DNO_CONFIG_HEADER')
 
 extensions = [Extension('pyscipopt.scip', [os.path.join(packagedir, 'scip'+ext)],
                           include_dirs=[includedir],