https://github.com/voyageur/openglide/pull/25

diff -Naur dosbox.orig/configure.ac dosbox/configure.ac
--- dosbox.orig/configure.ac	2021-10-26 13:06:35.585761330 +0100
+++ dosbox/configure.ac	2021-10-26 13:07:31.641323631 +0100
@@ -20,6 +20,12 @@
 AC_PROG_RANLIB
 AM_PROG_AR

+dnl The dlopen() function is in the C library for *BSD and in
+dnl libdl on GLIBC-based systems
+AC_SEARCH_LIBS([dlopen], [dl dld], [], [
+  AC_MSG_ERROR([unable to find the dlopen() function])
+])
+
 dnl Some needed libaries for OS2
 dnl perharps join this with the other target depended checks. move them upwards
 if test x$host = xi386-pc-os2-emx ; then