Fix "error: unknown type name 'cpu_set_t'".  Patch submitted upstream
http://lists.mcs.anl.gov/pipermail/petsc-dev/2014-May/015345.html

--- a/src/sys/threadcomm/impls/openmp/tcopenmp.c	2014-03-13 21:47:22.000000000 -0500
+++ b/src/sys/threadcomm/impls/openmp/tcopenmp.c	2014-04-02 14:44:57.185170151 -0500
@@ -1,6 +1,9 @@
 #define PETSC_DESIRE_FEATURE_TEST_MACROS
 #include <../src/sys/threadcomm/impls/openmp/tcopenmpimpl.h>
 #include <omp.h>
+#if defined(PETSC_HAVE_SCHED_CPU_SET_T)
+#include <sched.h>
+#endif
 
 PetscErrorCode PetscThreadCommGetRank_OpenMP(PetscInt *trank)
 {
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<tr><td><span title='2021-12-13 17:48:25 +0100'>2021-12-13</span></td><td><a href='/guix/commit/gnu/packages/rails.scm?id=8394619baceb118df92e355377fd543bb1aa501a'>gnu: Simplify package inputs.</a></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2021-06-13 23:57:45 +0200'>2021-06-13</span></td><td><a href='/guix/commit/gnu/packages/rails.scm?id=483f537081b9b5ccf026373d6743761aba6946e3'>doc, gnu, guix: Fix typos.</a></td><td>Paul A. Patience</td></tr>
<tr><td><span title='2021-02-23 16:04:27 +0200'>2021-02-23</span></td><td><a href='/guix/commit/gnu/packages/rails.scm?id=3c548c3e0eade12d3e86b1201dbd95863ca64ea7'>gnu: ruby-rails: Update to 6.1.3.</a></td><td>Efraim Flashner</td></tr>
<tr><td><span title='2021-02-23 16:04:27 +0200'>2021-02-23</span></td><td><a href='/guix/commit/gnu/packages/rails.scm?id=fa0a244138196604cb735691493bed5c71477248'>gnu: ruby-web-console: Update to 4.1.0.</a></td><td>Efraim Flashner</td></tr>
<tr><td><span title='2021-02-23 16:04:26 +0200'>2021-02-23</span></td><td><a href='/guix/commit/gnu/packages/rails.scm?id=6519e611293fd1b89dd3085fdbb99d8887116170'>gnu: ruby-rails-html-sanitizer: Update to 1.3.0.</a></td><td>Efraim Flashner</td></tr>
<tr><td><span title='2021-02-23 16:04:26 +0200'>2021-02-23</span></td><td><a href='/guix/commit/gnu/packages/rails.scm?id=945d5d039ac81489eba40c35ef6ea53ba8b26f7b'>gnu: ruby-rails-dom-testing: Update to 2.0.3.</a></td><td>Efraim Flashner</td></tr>