commit 58e6fe334e55f56eeb0211c10697be4d4a8c52b6
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Fri Jan 13 16:37:57 2023

    libstdc++: Add <errno.h> to <bits/std_mutex.h>
    
    This needs to be included explicitly now that we don't include all of
    <system_error> here.
    
    libstdc++-v3/ChangeLog:
    
            * include/bits/std_mutex.h: Include <errno.h>.

diff --git a/libstdc++-v3/include/bits/std_mutex.h b/libstdc++-v3/include/bits/std_mutex.h
index bc515358d23..f74ddc4123a 100644
--- a/libstdc++-v3/include/bits/std_mutex.h
+++ b/libstdc++-v3/include/bits/std_mutex.h
@@ -36,6 +36,7 @@
 # include <bits/c++0x_warning.h>
 #else
 
+#include <errno.h> // EBUSY
 #include <bits/functexcept.h>
 #include <bits/gthr.h>