The expanded sources for os_io.c on RHEL 4.2 show

# 23 "/usr/include/bits/sigset.h" 3 4 typedef int __sig_atomic_t;

typedef struct { unsigned long int __val[(1024 / (8 * sizeof (unsigned long int)))]; } __sigset_t;

then

# 35 "/usr/include/sys/select.h" 2 3 4

typedef __sigset_t sigset_t;

then

# 5958 "os_io.c" typedef sigset_t sigset_type;

static sigset_type block_signal (int signum)

{ sigset_type oldmask = 0;

sigset_type toblock;

sigemptyset (&toblock); sigaddset (&toblock, signum); sigprocmask (0, &toblock, &oldmask); # 5986 "os_io.c" return oldmask; }

and gcc rightly complains:

gcc -I../include -I. -Wall -W -Wno-unused -O1 -fno-math-errno - fschedule-insns2 -fno-trapping-math -fno-strict-aliasing -fwrapv - fomit-frame-pointer -fPIC -fno-common -mieee-fp -save-temps - DHAVE_CONFIG_H -D___PRIMAL -D___LIBRARY -D___GAMBCDIR=""/pkgs/ Gambit-C//v4.1.2"" -D___SYS_TYPE_CPU=""x86_64"" - D___SYS_TYPE_VENDOR=""unknown"" -D___SYS_TYPE_OS=""linux-gnu"" - c os_io.c os_io.c: In function â: os_io.c:5968: error: invalid initializer

So I suggest you change os_io.c from

___HIDDEN sigset_type block_signal ___P((int signum), (signum) int signum;) { sigset_type oldmask = 0;

to

___HIDDEN sigset_type block_signal ___P((int signum), (signum) int signum;) { sigset_type oldmask;

Brad