--- configure.orig	2019-10-02 07:02:19.000000000 +0200
+++ configure	2021-11-22 23:55:41.696433000 +0100
@@ -9041,6 +9041,28 @@
 esac
 
 case "$target_os" in #(
+  bsdsunix*) :
+
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether pthread should be enabled by default" >&5
+$as_echo_n "checking whether pthread should be enabled by default... " >&6; }
+if ${rb_cv_enable_pthread_default+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+_ACEOF
+if ac_fn_c_try_cpp "$LINENO"; then :
+  rb_cv_enable_pthread_default=yes
+else
+  rb_cv_enable_pthread_default=no
+fi
+rm -f conftest.err conftest.i conftest.$ac_ext
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $rb_cv_enable_pthread_default" >&5
+    colorize_result "$rb_cv_enable_pthread_default" ; }
+  enable_pthread=$rb_cv_enable_pthread_default
+   ;; #(
   freebsd*) :
 
   { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether pthread should be enabled by default" >&5
@@ -9555,7 +9577,7 @@
 		$as_echo "#define BROKEN_SETREGID 1" >>confdefs.h
 
                 ac_cv_sizeof_rlim_t=8 ;; #(
-  freebsd*) :
+  bsdsunix*|freebsd*) :
     	LIBS="-lm $LIBS"
 		ac_cv_func_getpeername=no
 		ac_cv_func_getsockname=no
@@ -20124,7 +20146,7 @@
 esac
 
 case "$target_os" in #(
-  freebsd*) :
+  bsdsunix*|freebsd*) :
 
 	 $as_echo "#define BROKEN_CLOSE 1" >>confdefs.h
 
@@ -24512,7 +24534,7 @@
 			XLDFLAGS="$XLDFLAGS -Wl,-E"
 			LIBPATHFLAG=" -L%1\$-s"
 			rb_cv_dlopen=yes ;; #(
-  freebsd*|dragonfly*) :
+  bsdsunix*|freebsd*|dragonfly*) :
 
 			: ${LDSHARED='$(CC) -shared'}
 			if test "$rb_cv_binary_elf" = yes; then
@@ -24712,7 +24734,7 @@
 fi
 
 case "$target_os" in #(
-  freebsd*) :
+  bsdsunix*|freebsd*) :
 
     { $as_echo "$as_me:${as_lineno-$LINENO}: checking for procstat_open_sysctl in -lprocstat" >&5
 $as_echo_n "checking for procstat_open_sysctl in -lprocstat... " >&6; }
@@ -24850,7 +24872,7 @@
 done
 
     fi ;; #(
-  *-freebsd*|x86_64-netbsd*) :
+  *-bsdsunix*|*-freebsd*|x86_64-netbsd*) :
 
     for ac_header in execinfo.h
 do :
@@ -25542,7 +25564,7 @@
   libdir_basename="${libdir_basename}"${multiarch+'/${arch}'}
 
   case "$target_os" in #(
-  freebsd*|dragonfly*) :
+  bsdsunix*|freebsd*|dragonfly*) :
      ;; #(
   *) :
 
@@ -25634,7 +25656,7 @@
 	    LIBRUBY_RELATIVE=yes
 	fi
 	 ;; #(
-  freebsd*|dragonfly*) :
+  bsdsunix*|freebsd*|dragonfly*) :
 
 	SOLIBS='$(LIBS)'
 	LIBRUBY_SO='lib$(RUBY_SO_NAME).so.$(MAJOR)$(MINOR)'
@@ -26076,7 +26098,7 @@
 
 fi
     case "${target_os}" in #(
-  freebsd*) :
+  bsdsunix*|freebsd*) :
             # FreeBSD's dtrace requires libelf
         LIBS="-lelf $LIBS"
      ;; #(