diff --git a/src/subshell/common.c b/src/subshell/common.c
--- a/src/subshell/common.c
+++ b/src/subshell/common.c
@@ -95,6 +95,45 @@
 #endif
 #endif
 
+#ifdef __redox__
+static int
+mc_posix_openpt (int flags)
+{
+    (void) flags;
+    errno = ENOSYS;
+    return -1;
+}
+
+static int
+mc_grantpt (int fd)
+{
+    (void) fd;
+    errno = ENOSYS;
+    return -1;
+}
+
+static int
+mc_unlockpt (int fd)
+{
+    (void) fd;
+    errno = ENOSYS;
+    return -1;
+}
+
+static char *
+mc_ptsname (int fd)
+{
+    (void) fd;
+    errno = ENOSYS;
+    return NULL;
+}
+
+#define posix_openpt mc_posix_openpt
+#define grantpt mc_grantpt
+#define unlockpt mc_unlockpt
+#define ptsname mc_ptsname
+#endif
+
 #include "lib/global.h"
 
 #include "lib/fileloc.h"
diff --git a/configure b/configure
--- a/configure
+++ b/configure
@@ -24408,10 +24408,10 @@
   fi
 
   if test -z "$ac_list_mounted_fs"; then
-    as_fn_error $? "could not determine how to read list of mounted file systems" "$LINENO" 5
-    # FIXME -- no need to abort building the whole package
-    # Can't build mountlist.c or anything that needs its functions
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: could not determine how to read list of mounted file systems" >&5
+printf "%s\n" "$as_me: WARNING: could not determine how to read list of mounted file systems" >&2; }
+    ac_list_mounted_fs=missing
   fi
 
   if test $ac_list_mounted_fs = found; then
     gl_cv_list_mounted_fs=yes