- d822181467ec41f1ee2d840c3c5b1918c72ffc86 introduced a bunch of gawk-isms.
- nproc doesn't exist on OpenBSD

Index: afl-cmin.awk
--- afl-cmin.awk.orig
+++ afl-cmin.awk
@@ -10,7 +10,7 @@ test "$SYS" = "Darwin" && {
 export AFL_QUIET=1
 export ASAN_OPTIONS=detect_leaks=0
 export PATH="${THISPATH}:$PATH"
-awk -f - -- ${@+"$@"} <<'EOF'
+gawk -f - -- ${@+"$@"} <<'EOF'
 #!/usr/bin/awk -f
 # awk script to minimize a test corpus of input files
 #
@@ -377,7 +377,7 @@ BEGIN {
   }
 
   if (threads) {
-    cmd = "nproc"
+    cmd = "getconf NPROCESSORS_ONLN"
     cmd | getline nproc
     close(cmd)
     if (threads == "all") {
