diff -up src/module_list.py.orig src/module_list.py
--- src/module_list.py.orig	2015-11-02 18:12:21.186706786 -0200
+++ src/module_list.py	2015-11-02 18:12:48.252707822 -0200
@@ -116,7 +116,6 @@ library_order["stdc++"] = 1000
 ###
 #############################################################
 
-from sage_setup.optional_extension import OptionalExtension
 UNAME = os.uname()
 
 def uname_specific(name, value, alternative):
@@ -338,21 +337,21 @@ ext_modules = [
               libraries = ['flint'],
               extra_compile_args = ['-std=c99']),
 
-    OptionalExtension("sage.graphs.mcqd",
-              ["sage/graphs/mcqd.pyx"],
-              language = "c++",
-              package = 'mcqd'),
-
-    OptionalExtension("sage.graphs.bliss",
-              ["sage/graphs/bliss.pyx"],
-              language = "c++",
-              libraries = ['bliss'],
-              package = 'bliss'),
-
-    OptionalExtension('sage.graphs.modular_decomposition',
-              sources = ['sage/graphs/modular_decomposition.pyx'],
-              libraries = ['modulardecomposition'],
-              package = 'modular_decomposition'),
+#    Extension("sage.graphs.mcqd",
+#              ["sage/graphs/mcqd.pyx"],
+#              language = "c++",
+#              package = 'mcqd'),
+
+#    Extension("sage.graphs.bliss",
+#              ["sage/graphs/bliss.pyx"],
+#              language = "c++",
+#              libraries = ['bliss'],
+#              package = 'bliss'),
+
+#    Extension('sage.graphs.modular_decomposition',
+#              sources = ['sage/graphs/modular_decomposition.pyx'],
+#              libraries = ['modulardecomposition'],
+#              package = 'modular_decomposition'),
 
     Extension('sage.graphs.planarity',
               sources = ['sage/graphs/planarity.pyx'],
@@ -504,19 +503,19 @@ ext_modules = [
     ##
     ################################
 
-    OptionalExtension('sage.libs.coxeter3.coxeter',
-              sources = ['sage/libs/coxeter3/coxeter.pyx'],
-              include_dirs = [os.path.join(SAGE_INC, 'coxeter')],
-              language="c++",
-              libraries = ['coxeter3'],
-              package = 'coxeter3'),
+#    Extension('sage.libs.coxeter3.coxeter',
+#              sources = ['sage/libs/coxeter3/coxeter.pyx'],
+#              include_dirs = [os.path.join(SAGE_INC, 'coxeter')],
+#              language="c++",
+#              libraries = ['coxeter3'],
+#              package = 'coxeter3'),
 
     Extension('sage.libs.ecl',
               sources = ["sage/libs/ecl.pyx"],
               libraries = ["ecl"],
               depends = [SAGE_INC + '/ecl/ecl.h']),
 
-    OptionalExtension("sage.libs.fes",
+    Extension("sage.libs.fes",
              ["sage/libs/fes.pyx"],
              language = "c",
              libraries = ['fes'],
@@ -988,13 +987,6 @@ ext_modules = [
 
     Extension('*', ['sage/misc/*.pyx']),
 
-    # Only include darwin_utilities on OS_X >= 10.5
-    OptionalExtension('sage.misc.darwin_utilities',
-        sources = ['sage/misc/darwin_memory_usage.c',
-                   'sage/misc/darwin_utilities.pyx'],
-        depends = ['sage/misc/darwin_memory_usage.h'],
-        condition = (UNAME[0] == "Darwin" and not UNAME[2].startswith('8.'))),
-
     ################################
     ##
     ## sage.modular
@@ -1122,19 +1114,7 @@ ext_modules = [
               language = 'c++',
               libraries=["gmp", "glpk", "z"]),
 
-    OptionalExtension("sage.numerical.backends.gurobi_backend",
-              ["sage/numerical/backends/gurobi_backend.pyx"],
-              libraries = ["stdc++", "gurobi"],
-              condition = os.path.isfile(SAGE_INC + "/gurobi_c.h") and
-                  os.path.isfile(SAGE_LOCAL + "/lib/libgurobi.so")),
-
-    OptionalExtension("sage.numerical.backends.cplex_backend",
-              ["sage/numerical/backends/cplex_backend.pyx"],
-              libraries = ["stdc++", "cplex"],
-              condition = os.path.isfile(SAGE_INC + "/cplex.h") and
-                  os.path.isfile(SAGE_LOCAL + "/lib/libcplex.a")),
-
-    OptionalExtension("sage.numerical.backends.coin_backend",
+    Extension("sage.numerical.backends.coin_backend",
               ["sage/numerical/backends/coin_backend.pyx"],
               language = 'c++',
               libraries = ["Cbc", "CbcSolver", "Cgl", "Clp", "CoinUtils", "OsiCbc", "OsiClp", "Osi", "lapack"],
@@ -1234,7 +1214,7 @@ ext_modules = [
               libraries=['ntl'],
               language = 'c++'),
 
-    OptionalExtension("sage.rings.complex_ball_acb",
+    Extension("sage.rings.complex_ball_acb",
                       ["sage/rings/complex_ball_acb.pyx"],
                       libraries=['arb', 'mpfi', 'mpfr'],
                       include_dirs=[SAGE_INC + '/flint'],
@@ -1307,7 +1287,7 @@ ext_modules = [
     Extension('sage.rings.real_interval_absolute',
               sources = ['sage/rings/real_interval_absolute.pyx']),
 
-    OptionalExtension("sage.rings.real_arb",
+    Extension("sage.rings.real_arb",
                       ["sage/rings/real_arb.pyx"],
                       libraries = ['arb', 'mpfi', 'mpfr'],
                       include_dirs = [SAGE_INC + '/flint'],
@@ -1602,14 +1582,14 @@ ext_modules = [
     ##
     ################################
 
-    OptionalExtension("sage.sat.solvers.cryptominisat.cryptominisat",
+    Extension("sage.sat.solvers.cryptominisat.cryptominisat",
               sources = ["sage/sat/solvers/cryptominisat/cryptominisat.pyx"],
               include_dirs = [os.path.join(SAGE_INC, "cmsat")],
               language = "c++",
               libraries = ['cryptominisat', 'z'],
               package = 'cryptominisat'),
 
-    OptionalExtension("sage.sat.solvers.cryptominisat.solverconf",
+    Extension("sage.sat.solvers.cryptominisat.solverconf",
               sources = ["sage/sat/solvers/cryptominisat/solverconf.pyx", "sage/sat/solvers/cryptominisat/solverconf_helper.cpp"],
               include_dirs = [os.path.join(SAGE_INC, "cmsat")],
               language = "c++",