Given two identical builds, using "identical" .jars, gcj dies on one but not the
other vis (running under fcatch is optional):

$ gcc --version
gcc (GCC) 4.1.2 20071124 (Red Hat 4.1.2-38)
[...]
$ pwd
/notnfs/cagney/devel/frysk/RHEL-5/frysk-0.0.1.2008.01.14/build/frysk-core
$ fcatch -- /usr/libexec/gcc/x86_64-redhat-linux/4.1.2/jc1
~/devel/frysk/RHEL-5/frysk-0.0.1.2008.01.14/build/frysk-core/frysk-core.jar
-fhash-synchronization -fno-use-divide-subroutine -fuse-boehm-gc
-fnon-call-exceptions -fkeep-inline-functions -quiet -dumpbase frysk-core.jar
-mtune=generic -auxbase frysk-core -g -O -Wextraneous-semicolon -Wall -Werror
-version -fPIC -I../../frysk-core -I. -I../frysk-sys/frysk-sys.jar
-I../frysk-imports/jline.jar -I../frysk-imports/antlr.jar
-I../frysk-imports/junit.jar -I../frysk-imports/getopt.jar
-I../frysk-imports/jdom.jar -I../frysk-imports/cdtparser.jar -o /tmp/ccICWoyY.s
[...]
$

vs:

$ gcc --version
gcc (GCC) 4.1.2 20071124 (Red Hat 4.1.2-38)
[...]
$ pwd
/notnfs/cagney/devel/frysk/RHEL-5/frysk-0.0.1.2008.01.14/build/frysk-core
$ fcatch -- /usr/libexec/gcc/x86_64-redhat-linux/4.1.2/jc1 frysk-core.jar
-fhash-synchronization -fno-use-divide-subroutine -fuse-boehm-gc
-fnon-call-exceptions -fkeep-inline-functions -quiet -dumpbase frysk-core.jar
-mtune=generic -auxbase frysk-core -g -O -Wextraneous-semicolon -Wall -Werror
-version -fPIC -I../../frysk-core -I. -I../frysk-sys/frysk-sys.jar
-I../frysk-imports/jline.jar -I../frysk-imports/antlr.jar
-I../frysk-imports/junit.jar -I../frysk-imports/getopt.jar
-I../frysk-imports/jdom.jar -I../frysk-imports/cdtparser.jar -o /tmp/ccICWoyY.s
Entered parseCommand
GNU Java version 4.1.2 20071124 (Red Hat 4.1.2-38) (x86_64-redhat-linux)
        compiled by GNU C version 4.1.2 20071124 (Red Hat 4.1.2-38).
GGC heuristics: --param ggc-min-expand=98 --param ggc-min-heapsize=128293
Class path starts here:
    ../../frysk-core/
    ./
    ../frysk-sys/frysk-sys.jar/ (zip)
    ../frysk-imports/jline.jar/ (zip)
    ../frysk-imports/antlr.jar/ (zip)
    ../frysk-imports/junit.jar/ (zip)
    ../frysk-imports/getopt.jar/ (zip)
    ../frysk-imports/jdom.jar/ (zip)
    ../frysk-imports/cdtparser.jar/ (zip)
    ./
    /usr/share/java/libgcj-4.1.2.jar/ (system) (zip)
fcatch: from PID 26984 TID 26984:
SIGSEGV detected - dumping stack trace for TID 26984
#0 0x000000000045f9d5 in mark_reference_fields () from
/usr/libexec/gcc/x86_64-redhat-linux/4.1.1/jc1
#1 0x000000000045fd2f in mark_reference_fields () from
/usr/libexec/gcc/x86_64-redhat-linux/4.1.1/jc1
#2 0x000000000045fe4a in get_boehm_type_descriptor () from
/usr/libexec/gcc/x86_64-redhat-linux/4.1.1/jc1
#3 0x000000000042e9fc in make_class_data () from
/usr/libexec/gcc/x86_64-redhat-linux/4.1.1/jc1
#4 0x0000000000431b59 in finish_class () from
/usr/libexec/gcc/x86_64-redhat-linux/4.1.1/jc1
#5 0x000000000044e5e0 in parse_class_file () from
/usr/libexec/gcc/x86_64-redhat-linux/4.1.1/jc1
#6 0x0000000000451671 in java_parse_file () from
/usr/libexec/gcc/x86_64-redhat-linux/4.1.1/jc1
#7 0x00000000006e6d34 in toplev_main () from
/usr/libexec/gcc/x86_64-redhat-linux/4.1.1/jc1
#8 0x0000003efca1d8a4 in __libc_start_main () from /lib64/libc-2.5.so
#9 0x0000000000402749 in calloc@@GLIBC_2.2.5 () from
/usr/libexec/gcc/x86_64-redhat-linux/4.1.1/jc1

frysk/proc/live/LinuxPtraceTaskState.java:1470: internal compiler error:
Segmentation fault
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://bugzilla.redhat.com/bugzilla> for instructions.