See the illumos-joyent bug report for how the fix was originally tested.
After porting the fix upstream to illumos-joyent, I re-tested the change on my open indiana workstation. That output is captured below:
#
# Here's an fmd fltlog with a dozen or so entries
#
root@openindiana:/# fmdump
TIME UUID SUNW-MSG-ID EVENT
Nov 10 15:17:32.2011 8fc075a4-4ae1-c5c8-9bd5-d6e3540bca98 SUNOS-8000-J0 Diagnosed
Nov 10 16:14:37.0111 ba3254a3-e01b-4a89-e5b3-a30c6ab7852b SMF-8000-YX Diagnosed
Nov 10 16:16:29.1287 ba3254a3-e01b-4a89-e5b3-a30c6ab7852b FMD-8000-4M Repaired
Nov 10 16:16:29.1513 ba3254a3-e01b-4a89-e5b3-a30c6ab7852b FMD-8000-6U Resolved
Nov 13 06:54:41.2248 a7ea3e63-58c8-6f53-8bf6-8915308e9d62 SMF-8000-YX Diagnosed
Nov 18 13:44:37.8118 a7ea3e63-58c8-6f53-8bf6-8915308e9d62 FMD-8000-4M Repaired
Nov 18 13:44:37.8312 a7ea3e63-58c8-6f53-8bf6-8915308e9d62 FMD-8000-6U Resolved
Nov 18 13:44:39.0666 c7933e94-a212-42aa-ccd2-ad143b51bbe2 SMF-8000-YX Diagnosed
Nov 22 00:13:28.6937 c7933e94-a212-42aa-ccd2-ad143b51bbe2 FMD-8000-4M Repaired
Nov 22 00:13:28.7013 c7933e94-a212-42aa-ccd2-ad143b51bbe2 FMD-8000-6U Resolved
Dec 07 06:56:01.1395 db05f2d8-9802-e581-85ff-a48a034c004a SMF-8000-YX Diagnosed
Dec 07 07:01:09.4506 db05f2d8-9802-e581-85ff-a48a034c004a FMD-8000-4M Repaired
Dec 07 07:01:09.4521 db05f2d8-9802-e581-85ff-a48a034c004a FMD-8000-6U Resolved
Dec 07 07:02:09.4651 fedfc2e2-336b-64b8-8ec1-dceffbd4ca8e SMF-8000-YX Diagnosed
Dec 07 07:05:59.6805 fedfc2e2-336b-64b8-8ec1-dceffbd4ca8e FMD-8000-4M Repaired
Dec 07 07:05:59.6904 fedfc2e2-336b-64b8-8ec1-dceffbd4ca8e FMD-8000-6U Resolved
#
# Move a couple of the message files aside so that some of the lookups will fail
#
root@openindiana:/# mv /usr/lib/locale/C/LC_MESSAGES/SMF.mo /var/tmp
root@openindiana:/# mv /usr/lib/locale/C/LC_MESSAGES/SUNOS.mo /var/tmp
#
# First here's the unhelpful error you get from the stock fmdump binary:
#
root@openindiana:/# fmdump -m
fmdump: failed to format message: No such file or directory
fmdump: warning: failed to dump /var/fm/fmd/fltlog: Error 0
root@openindiana:/# echo $?
3
#
# And here's output running the fixed fmdump binary out the proto area of my workspace
#
root@openindiana:/# ~rejohnst/ws/illumos-upstream1/proto/root_i386/usr/sbin/fmdump -m
/export/home/rejohnst/ws/illumos-upstream1/proto/root_i386/usr/sbin/fmdump: failed to format message for diagcode SUNOS-8000-J0, event 8fc075a4-4ae1-c5c8-9bd5-d6e3540bca98: No such file or directory
/export/home/rejohnst/ws/illumos-upstream1/proto/root_i386/usr/sbin/fmdump: failed to format message for diagcode SMF-8000-YX, event ba3254a3-e01b-4a89-e5b3-a30c6ab7852b: No such file or directory
SUNW-MSG-ID: FMD-8000-4M, TYPE: Repair, VER: 1, SEVERITY: Minor
EVENT-TIME: Fri Nov 10 16:14:36 PST 2017
PLATFORM: System-Product-Name, CSN: System-Serial-Number, HOSTNAME: openindiana
SOURCE: software-diagnosis, REV: 0.1
EVENT-ID: ba3254a3-e01b-4a89-e5b3-a30c6ab7852b
DESC: All faults associated with an event id have been addressed.
Refer to http://illumos.org/msg/FMD-8000-4M for more information.
AUTO-RESPONSE: Some system components offlined because of the original fault may have been brought back online.
IMPACT: Performance degradation of the system due to the original fault may have been recovered.
REC-ACTION: Use fmdump -v -u <EVENT-ID> to identify the repaired components.
SUNW-MSG-ID: FMD-8000-6U, TYPE: Resolved, VER: 1, SEVERITY: Minor
EVENT-TIME: Fri Nov 10 16:14:36 PST 2017
PLATFORM: System-Product-Name, CSN: System-Serial-Number, HOSTNAME: openindiana
SOURCE: software-diagnosis, REV: 0.1
EVENT-ID: ba3254a3-e01b-4a89-e5b3-a30c6ab7852b
DESC: All faults associated with an event id have been addressed.
Refer to http://illumos.org/msg/FMD-8000-6U for more information.
AUTO-RESPONSE: All system components offlined because of the original fault have been brought back online.
IMPACT: Performance degradation of the system due to the original fault has been recovered.
REC-ACTION: Use fmdump -v -u <EVENT-ID> to identify the repaired components.
/export/home/rejohnst/ws/illumos-upstream1/proto/root_i386/usr/sbin/fmdump: failed to format message for diagcode SMF-8000-YX, event a7ea3e63-58c8-6f53-8bf6-8915308e9d62: No such file or directory
SUNW-MSG-ID: FMD-8000-4M, TYPE: Repair, VER: 1, SEVERITY: Minor
EVENT-TIME: Mon Nov 13 06:54:41 PST 2017
PLATFORM: System-Product-Name, CSN: System-Serial-Number, HOSTNAME: openindiana
SOURCE: software-diagnosis, REV: 0.1
EVENT-ID: a7ea3e63-58c8-6f53-8bf6-8915308e9d62
DESC: All faults associated with an event id have been addressed.
Refer to http://illumos.org/msg/FMD-8000-4M for more information.
AUTO-RESPONSE: Some system components offlined because of the original fault may have been brought back online.
IMPACT: Performance degradation of the system due to the original fault may have been recovered.
REC-ACTION: Use fmdump -v -u <EVENT-ID> to identify the repaired components.
SUNW-MSG-ID: FMD-8000-6U, TYPE: Resolved, VER: 1, SEVERITY: Minor
EVENT-TIME: Mon Nov 13 06:54:41 PST 2017
PLATFORM: System-Product-Name, CSN: System-Serial-Number, HOSTNAME: openindiana
SOURCE: software-diagnosis, REV: 0.1
EVENT-ID: a7ea3e63-58c8-6f53-8bf6-8915308e9d62
DESC: All faults associated with an event id have been addressed.
Refer to http://illumos.org/msg/FMD-8000-6U for more information.
AUTO-RESPONSE: All system components offlined because of the original fault have been brought back online.
IMPACT: Performance degradation of the system due to the original fault has been recovered.
REC-ACTION: Use fmdump -v -u <EVENT-ID> to identify the repaired components.
/export/home/rejohnst/ws/illumos-upstream1/proto/root_i386/usr/sbin/fmdump: failed to format message for diagcode SMF-8000-YX, event c7933e94-a212-42aa-ccd2-ad143b51bbe2: No such file or directory
SUNW-MSG-ID: FMD-8000-4M, TYPE: Repair, VER: 1, SEVERITY: Minor
EVENT-TIME: Sat Nov 18 13:44:39 PST 2017
PLATFORM: System-Product-Name, CSN: System-Serial-Number, HOSTNAME: openindiana
SOURCE: software-diagnosis, REV: 0.1
EVENT-ID: c7933e94-a212-42aa-ccd2-ad143b51bbe2
DESC: All faults associated with an event id have been addressed.
Refer to http://illumos.org/msg/FMD-8000-4M for more information.
AUTO-RESPONSE: Some system components offlined because of the original fault may have been brought back online.
IMPACT: Performance degradation of the system due to the original fault may have been recovered.
REC-ACTION: Use fmdump -v -u <EVENT-ID> to identify the repaired components.
SUNW-MSG-ID: FMD-8000-6U, TYPE: Resolved, VER: 1, SEVERITY: Minor
EVENT-TIME: Sat Nov 18 13:44:39 PST 2017
PLATFORM: System-Product-Name, CSN: System-Serial-Number, HOSTNAME: openindiana
SOURCE: software-diagnosis, REV: 0.1
EVENT-ID: c7933e94-a212-42aa-ccd2-ad143b51bbe2
DESC: All faults associated with an event id have been addressed.
Refer to http://illumos.org/msg/FMD-8000-6U for more information.
AUTO-RESPONSE: All system components offlined because of the original fault have been brought back online.
IMPACT: Performance degradation of the system due to the original fault has been recovered.
REC-ACTION: Use fmdump -v -u <EVENT-ID> to identify the repaired components.
/export/home/rejohnst/ws/illumos-upstream1/proto/root_i386/usr/sbin/fmdump: failed to format message for diagcode SMF-8000-YX, event db05f2d8-9802-e581-85ff-a48a034c004a: No such file or directory
SUNW-MSG-ID: FMD-8000-4M, TYPE: Repair, VER: 1, SEVERITY: Minor
EVENT-TIME: Thu Dec 7 06:56:01 PST 2017
PLATFORM: System-Product-Name, CSN: System-Serial-Number, HOSTNAME: openindiana
SOURCE: fmd, REV: 1.2
EVENT-ID: db05f2d8-9802-e581-85ff-a48a034c004a
DESC: All faults associated with an event id have been addressed.
Refer to http://illumos.org/msg/FMD-8000-4M for more information.
AUTO-RESPONSE: Some system components offlined because of the original fault may have been brought back online.
IMPACT: Performance degradation of the system due to the original fault may have been recovered.
REC-ACTION: Use fmdump -v -u <EVENT-ID> to identify the repaired components.
SUNW-MSG-ID: FMD-8000-6U, TYPE: Resolved, VER: 1, SEVERITY: Minor
EVENT-TIME: Thu Dec 7 06:56:01 PST 2017
PLATFORM: System-Product-Name, CSN: System-Serial-Number, HOSTNAME: openindiana
SOURCE: fmd, REV: 1.2
EVENT-ID: db05f2d8-9802-e581-85ff-a48a034c004a
DESC: All faults associated with an event id have been addressed.
Refer to http://illumos.org/msg/FMD-8000-6U for more information.
AUTO-RESPONSE: All system components offlined because of the original fault have been brought back online.
IMPACT: Performance degradation of the system due to the original fault has been recovered.
REC-ACTION: Use fmdump -v -u <EVENT-ID> to identify the repaired components.
/export/home/rejohnst/ws/illumos-upstream1/proto/root_i386/usr/sbin/fmdump: failed to format message for diagcode SMF-8000-YX, event fedfc2e2-336b-64b8-8ec1-dceffbd4ca8e: No such file or directory
SUNW-MSG-ID: FMD-8000-4M, TYPE: Repair, VER: 1, SEVERITY: Minor
EVENT-TIME: Thu Dec 7 07:02:09 PST 2017
PLATFORM: System-Product-Name, CSN: System-Serial-Number, HOSTNAME: openindiana
SOURCE: software-diagnosis, REV: 0.1
EVENT-ID: fedfc2e2-336b-64b8-8ec1-dceffbd4ca8e
DESC: All faults associated with an event id have been addressed.
Refer to http://illumos.org/msg/FMD-8000-4M for more information.
AUTO-RESPONSE: Some system components offlined because of the original fault may have been brought back online.
IMPACT: Performance degradation of the system due to the original fault may have been recovered.
REC-ACTION: Use fmdump -v -u <EVENT-ID> to identify the repaired components.
SUNW-MSG-ID: FMD-8000-6U, TYPE: Resolved, VER: 1, SEVERITY: Minor
EVENT-TIME: Thu Dec 7 07:02:09 PST 2017
PLATFORM: System-Product-Name, CSN: System-Serial-Number, HOSTNAME: openindiana
SOURCE: software-diagnosis, REV: 0.1
EVENT-ID: fedfc2e2-336b-64b8-8ec1-dceffbd4ca8e
DESC: All faults associated with an event id have been addressed.
Refer to http://illumos.org/msg/FMD-8000-6U for more information.
AUTO-RESPONSE: All system components offlined because of the original fault have been brought back online.
IMPACT: Performance degradation of the system due to the original fault has been recovered.
REC-ACTION: Use fmdump -v -u <EVENT-ID> to identify the repaired components.
root@openindiana:/# echo $?
3