diff -up src/module_list.py.orig src/module_list.py
--- src/module_list.py.orig	2020-01-01 04:03:10.000000000 -0700
+++ src/module_list.py	2020-02-25 13:38:22.980350735 -0700
@@ -389,16 +389,16 @@ ext_modules = [
     Extension('sage.graphs.matchpoly',
               sources = ['sage/graphs/matchpoly.pyx']),
 
-    OptionalExtension("sage.graphs.mcqd",
+    Extension("sage.graphs.mcqd",
               ["sage/graphs/mcqd.pyx"],
               language = "c++",
-              package = 'mcqd'),
+              libraries = ['mcqd']),
 
-    OptionalExtension("sage.graphs.bliss",
+    Extension("sage.graphs.bliss",
               ["sage/graphs/bliss.pyx"],
               language = "c++",
-              libraries = ['bliss'],
-              package = 'bliss'),
+              include_dirs = ['/usr/include/bliss'],
+              libraries = ['bliss']),
 
     Extension('sage.graphs.planarity',
               sources = ['sage/graphs/planarity.pyx'],
@@ -417,10 +417,9 @@ ext_modules = [
     Extension('sage.graphs.graph_decompositions.cutwidth',
               sources = ['sage/graphs/graph_decompositions/cutwidth.pyx']),
 
-    OptionalExtension('sage.graphs.graph_decompositions.tdlib',
+    Extension('sage.graphs.graph_decompositions.tdlib',
               sources = ['sage/graphs/graph_decompositions/tdlib.pyx'],
-              language="c++",
-              package = 'tdlib'),
+              language="c++"),
 
     Extension('sage.graphs.spanning_tree',
               sources = ['sage/graphs/spanning_tree.pyx']),
@@ -479,9 +478,9 @@ ext_modules = [
     ##
     ################################
 
-    OptionalExtension("sage.interfaces.primecount",
+    Extension("sage.interfaces.primecount",
               ["sage/interfaces/primecount.pyx"],
-              package = "primecount"),
+              libraries = ["primecount"]),
 
     Extension('*', ['sage/interfaces/*.pyx']),
 
@@ -500,21 +499,19 @@ ext_modules = [
     ##
     ################################
 
-    OptionalExtension('sage.libs.coxeter3.coxeter',
+    Extension('sage.libs.coxeter3.coxeter',
               sources = ['sage/libs/coxeter3/coxeter.pyx'],
-              include_dirs = [os.path.join(SAGE_INC, 'coxeter')],
+              include_dirs = ['/usr/include/coxeter'],
               language="c++",
-              libraries = ['coxeter3'],
-              package = 'coxeter3'),
+              libraries = ['coxeter3']),
 
     Extension('sage.libs.ecl',
               sources = ["sage/libs/ecl.pyx"]),
 
-    OptionalExtension("sage.libs.fes",
+    Extension("sage.libs.fes",
              ["sage/libs/fes.pyx"],
              language = "c",
-             libraries = ['fes'],
-             package = 'fes'),
+             libraries = ['fes']),
 
     Extension('sage.libs.flint.flint',
               sources = ["sage/libs/flint/flint.pyx"],
@@ -543,13 +540,14 @@ ext_modules = [
                       sources = ["sage/libs/homfly.pyx"],
                       libraries = ["homfly", "gc"]),
 
-    OptionalExtension('sage.libs.sirocco',
+    Extension('sage.libs.sirocco',
                       sources = ["sage/libs/sirocco.pyx"],
                       libraries = ["sirocco"],
-                      package="sirocco",
                       language = 'c++'),
 
-    Extension('*', ['sage/libs/linbox/*.pyx']),
+    Extension('*',
+                      sources = ['sage/libs/linbox/*.pyx'],
+                      libraries = ["gomp"]),
 
     Extension('sage.libs.lcalc.lcalc_Lfunction',
               sources = ['sage/libs/lcalc/lcalc_Lfunction.pyx'],
@@ -566,10 +564,9 @@ ext_modules = [
     Extension('sage.libs.lrcalc.lrcalc',
               sources = ["sage/libs/lrcalc/lrcalc.pyx"]),
 
-    OptionalExtension("sage.libs.meataxe",
+    Extension("sage.libs.meataxe",
               sources = ['sage/libs/meataxe.pyx'],
-              libraries = ['mtx'],
-              package = 'meataxe'),
+              libraries = ['mtx']),
 
     Extension('*', ['sage/libs/pari/*.pyx']),
 
@@ -815,7 +812,8 @@ ext_modules = [
               include_dirs = cblas_include_dirs),
 
     Extension('sage.matrix.matrix_integer_sparse',
-              sources = ['sage/matrix/matrix_integer_sparse.pyx']),
+              sources = ['sage/matrix/matrix_integer_sparse.pyx'],
+              libraries = ['gomp']),
 
     Extension('sage.matrix.matrix_mod2_dense',
               sources = ['sage/matrix/matrix_mod2_dense.pyx'],
@@ -834,20 +832,21 @@ ext_modules = [
     Extension('sage.matrix.matrix_modn_dense_float',
               sources = ['sage/matrix/matrix_modn_dense_float.pyx'],
               language="c++",
-              libraries = cblas_libs,
+              libraries = cblas_libs + ['gomp'],
               library_dirs = cblas_library_dirs,
               include_dirs = cblas_include_dirs),
 
     Extension('sage.matrix.matrix_modn_dense_double',
               sources = ['sage/matrix/matrix_modn_dense_double.pyx'],
               language="c++",
-              libraries = cblas_libs,
+              libraries = cblas_libs + ['gomp'],
               library_dirs = cblas_library_dirs,
               include_dirs = cblas_include_dirs,
               extra_compile_args = ["-D_XPG6"]),
 
     Extension('sage.matrix.matrix_modn_sparse',
-              sources = ['sage/matrix/matrix_modn_sparse.pyx']),
+              sources = ['sage/matrix/matrix_modn_sparse.pyx'],
+              libraries = ['gomp']),
 
     Extension('sage.matrix.matrix_mpolynomial_dense',
               sources = ['sage/matrix/matrix_mpolynomial_dense.pyx']),
@@ -877,10 +876,9 @@ ext_modules = [
     Extension('sage.matrix.matrix_window',
               sources = ['sage/matrix/matrix_window.pyx']),
 
-    OptionalExtension("sage.matrix.matrix_gfpn_dense",
+    Extension("sage.matrix.matrix_gfpn_dense",
               sources = ['sage/matrix/matrix_gfpn_dense.pyx'],
-              libraries = ['mtx'],
-              package = 'meataxe'),
+              libraries = ['mtx']),
 
     Extension('sage.matrix.misc',
               sources = ['sage/matrix/misc.pyx']),
@@ -1056,26 +1054,25 @@ ext_modules = [
     Extension("sage.numerical.backends.interactivelp_backend",
               ["sage/numerical/backends/interactivelp_backend.pyx"]),
 
-    OptionalExtension("sage.numerical.backends.gurobi_backend",
-              ["sage/numerical/backends/gurobi_backend.pyx"],
-              libraries = ["gurobi"],
-              condition = os.path.isfile(SAGE_INC + "/gurobi_c.h") and
-                  os.path.isfile(SAGE_LOCAL + "/lib/libgurobi.so")),
+#    OptionalExtension("sage.numerical.backends.gurobi_backend",
+#              ["sage/numerical/backends/gurobi_backend.pyx"],
+#              libraries = ["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 = ["cplex"],
-              condition = os.path.isfile(SAGE_INC + "/cplex.h") and
-                  os.path.isfile(SAGE_LOCAL + "/lib/libcplex.a")),
+#    OptionalExtension("sage.numerical.backends.cplex_backend",
+#              ["sage/numerical/backends/cplex_backend.pyx"],
+#              libraries = ["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_libs,
               library_dirs = lapack_library_dirs,
-              include_dirs = lapack_include_dirs,
-              package = 'cbc'),
+              include_dirs = lapack_include_dirs),
 
     ################################
     ##