diff --git a/cylc/flow/cfgspec/suite.py b/cylc/flow/cfgspec/suite.py
index f081b8486e0..3eb2c095b59 100644
--- a/cylc/flow/cfgspec/suite.py
+++ b/cylc/flow/cfgspec/suite.py
@@ -189,9 +189,6 @@
             tasks manually near the end of a suite run, during suite
             development and debugging.
         ''')
-        Conf('abort if any task fails', VDR.V_BOOLEAN, desc='''
-            TODO: Remove this at Cylc9
-        ''')
 
         with Conf('main loop'):
             with Conf('<plugin name>'):
@@ -1307,6 +1304,7 @@ def upg(cfg, descr):
         ['cylc', 'health check interval'])
     u.obsolete('8.0.0', ['runtime', '__MANY__', 'job', 'shell'])
     u.obsolete('8.0.0', ['cylc', 'abort if any task fails'])
+    u.obsolete('8.0.0', ['cylc', 'events', 'abort if any task fails'])
     # TODO uncomment these deprecations when ready - see todo in
     # [runtime][__MANY__] section.
     # for job_setting in [
diff --git a/cylc/flow/scheduler_cli.py b/cylc/flow/scheduler_cli.py
index a9b0c822ad9..039dd30996c 100644
--- a/cylc/flow/scheduler_cli.py
+++ b/cylc/flow/scheduler_cli.py
@@ -235,7 +235,7 @@ def get_option_parser(is_restart, add_std_opts=False):
     )
 
     parser.add_option(
-        "--abort-if-any-task-fails", "--fragile",
+        "--abort-if-any-task-fails",
         help="If set workflow will abort with status 1 if any task fails.",
         action="store_true", default=False, dest="abort_if_any_task_fails"
     )
diff --git a/tests/flakyfunctional/execution-time-limit/04-poll.t b/tests/flakyfunctional/execution-time-limit/04-poll.t
index 3bad2cbd6e3..6accf2533d9 100755
--- a/tests/flakyfunctional/execution-time-limit/04-poll.t
+++ b/tests/flakyfunctional/execution-time-limit/04-poll.t
@@ -18,6 +18,6 @@
 # Test execution time limit polling.
 . "$(dirname "$0")/test_header"
 set_test_number 2
-export ABORT_ON_TASK_FAIL='--fragile'
+export ABORT_ON_TASK_FAIL='--abort-if-any-task-fails'
 reftest
 exit
diff --git a/tests/functional/authentication/02-suite2-stop-suite1.t b/tests/functional/authentication/02-suite2-stop-suite1.t
index 6dcb328501f..b9a1aeb0579 100755
--- a/tests/functional/authentication/02-suite2-stop-suite1.t
+++ b/tests/functional/authentication/02-suite2-stop-suite1.t
@@ -42,7 +42,7 @@ __FLOW_CONFIG__
 cylc register "${NAME2}" "${SUITE2_RUND}"
 cylc run --no-detach "${NAME1}" 1>'1.out' 2>&1 &
 SUITE_RUN_DIR="${SUITE1_RUND}" poll_suite_running
-run_ok "${TEST_NAME_BASE}" cylc run --no-detach --fragile "${NAME2}"
+run_ok "${TEST_NAME_BASE}" cylc run --no-detach --abort-if-any-task-fails "${NAME2}"
 cylc shutdown "${NAME1}" --max-polls=20 --interval=1 1>'/dev/null' 2>&1 || true
 purge_suite "${NAME1}"
 purge_suite "${NAME2}"
diff --git a/tests/functional/broadcast/05-bad-point.t b/tests/functional/broadcast/05-bad-point.t
index c5f72b058b0..ee1e3249581 100755
--- a/tests/functional/broadcast/05-bad-point.t
+++ b/tests/functional/broadcast/05-bad-point.t
@@ -21,7 +21,7 @@ set_test_number 2
 install_suite "${TEST_NAME_BASE}" "${TEST_NAME_BASE}"
 
 run_ok "${TEST_NAME_BASE}-validate" cylc validate "${SUITE_NAME}"
-suite_run_ok "${TEST_NAME_BASE}" cylc run --debug --no-detach --fragile "${SUITE_NAME}"
+suite_run_ok "${TEST_NAME_BASE}" cylc run --debug --no-detach --abort-if-any-task-fails "${SUITE_NAME}"
 
 purge_suite "${SUITE_NAME}"
 exit
diff --git a/tests/functional/broadcast/06-bad-namespace.t b/tests/functional/broadcast/06-bad-namespace.t
index ac640e4354b..53f72cc577e 100755
--- a/tests/functional/broadcast/06-bad-namespace.t
+++ b/tests/functional/broadcast/06-bad-namespace.t
@@ -21,7 +21,7 @@ set_test_number 2
 install_suite "${TEST_NAME_BASE}" "${TEST_NAME_BASE}"
 
 run_ok "${TEST_NAME_BASE}-validate" cylc validate "${SUITE_NAME}"
-suite_run_ok "${TEST_NAME_BASE}" cylc run --debug --no-detach --fragile "${SUITE_NAME}"
+suite_run_ok "${TEST_NAME_BASE}" cylc run --debug --no-detach --abort-if-any-task-fails "${SUITE_NAME}"
 
 purge_suite "${SUITE_NAME}"
 exit
diff --git a/tests/functional/broadcast/07-timeout.t b/tests/functional/broadcast/07-timeout.t
index b10f3859211..cc81ebf1296 100755
--- a/tests/functional/broadcast/07-timeout.t
+++ b/tests/functional/broadcast/07-timeout.t
@@ -18,6 +18,6 @@
 # Test broadcasts a timeout setting
 . "$(dirname "$0")/test_header"
 set_test_number 2
-export ABORT_ON_TASK_FAIL='--fragile'
+export ABORT_ON_TASK_FAIL='--abort-if-any-task-fails'
 reftest
 exit
diff --git a/tests/functional/broadcast/08-space.t b/tests/functional/broadcast/08-space.t
index b6c3ea272c6..517a1e1c9ad 100755
--- a/tests/functional/broadcast/08-space.t
+++ b/tests/functional/broadcast/08-space.t
@@ -18,6 +18,6 @@
 # Test broadcast -s '[foo]  bar=baz' syntax. cylc/cylc-flow#1680
 . "$(dirname "$0")/test_header"
 set_test_number 2
-export ABORT_ON_TASK_FAIL='--fragile'
+export ABORT_ON_TASK_FAIL='--abort-if-any-task-fails'
 reftest
 exit
diff --git a/tests/functional/clock-expire/00-basic.t b/tests/functional/clock-expire/00-basic.t
index 1802228c15a..1a18d37ebbd 100644
--- a/tests/functional/clock-expire/00-basic.t
+++ b/tests/functional/clock-expire/00-basic.t
@@ -24,7 +24,7 @@ install_suite "${TEST_NAME_BASE}" "${TEST_NAME_BASE}"
 run_ok "${TEST_NAME_BASE}-validate" cylc validate "${SUITE_NAME}"
 
 suite_run_ok "${TEST_NAME_BASE}-run" \
-    cylc run --debug --no-detach --fragile "${SUITE_NAME}"
+    cylc run --debug --no-detach --abort-if-any-task-fails "${SUITE_NAME}"
 
 purge_suite "${SUITE_NAME}"
 exit
diff --git a/tests/functional/hold-release/05-release.t b/tests/functional/hold-release/05-release.t
index 45a84a20ea6..f4ffb35ac99 100755
--- a/tests/functional/hold-release/05-release.t
+++ b/tests/functional/hold-release/05-release.t
@@ -70,7 +70,7 @@ __FLOW_CONFIG__
 run_ok "${TEST_NAME_BASE}-val" cylc validate "${SUITE_NAME}"
 
 suite_run_ok "${TEST_NAME_BASE}-run" \
-    cylc run --debug --no-detach --fragile "${SUITE_NAME}"
+    cylc run --debug --no-detach --abort-if-any-task-fails "${SUITE_NAME}"
 
 # Should shut down with all non-released tasks in the held state, and dog1.1
 # finished and gone from the task pool.
diff --git a/tests/functional/hold-release/08-hold.t b/tests/functional/hold-release/08-hold.t
index f2ba2d6540c..752d52e49b7 100755
--- a/tests/functional/hold-release/08-hold.t
+++ b/tests/functional/hold-release/08-hold.t
@@ -70,7 +70,7 @@ __FLOW_CONFIG__
 run_ok "${TEST_NAME_BASE}-val" cylc validate "${SUITE_NAME}"
 
 suite_run_ok "${TEST_NAME_BASE}-run" \
-    cylc run --debug --no-detach --fragile "${SUITE_NAME}"
+    cylc run --debug --no-detach --abort-if-any-task-fails "${SUITE_NAME}"
 
 # Should shut down with all the held tasks in the held state, and dog.2
 # finished and gone from the task pool.
diff --git a/tests/functional/hold-release/18-hold-cycle-globs.t b/tests/functional/hold-release/18-hold-cycle-globs.t
index dcd903d3d71..3504b52c9f9 100755
--- a/tests/functional/hold-release/18-hold-cycle-globs.t
+++ b/tests/functional/hold-release/18-hold-cycle-globs.t
@@ -18,6 +18,6 @@
 # Test hold cycle point glob
 . "$(dirname "$0")/test_header"
 set_test_number 2
-export ABORT_ON_TASK_FAIL='--fragile'
+export ABORT_ON_TASK_FAIL='--abort-if-any-task-fails'
 reftest
 exit
diff --git a/tests/functional/hold-release/19-no-reset-prereq-on-waiting.t b/tests/functional/hold-release/19-no-reset-prereq-on-waiting.t
index 20147322e86..8213c9bc673 100755
--- a/tests/functional/hold-release/19-no-reset-prereq-on-waiting.t
+++ b/tests/functional/hold-release/19-no-reset-prereq-on-waiting.t
@@ -18,6 +18,6 @@
 # Test on release of a waiting task, don't reset its prerequisites
 . "$(dirname "$0")/test_header"
 set_test_number 2
-export ABORT_ON_TASK_FAIL='--fragile'
+export ABORT_ON_TASK_FAIL='--abort-if-any-task-fails'
 reftest
 exit
diff --git a/tests/functional/lib/bash/test_header b/tests/functional/lib/bash/test_header
index a04ee3fc5da..da610988aea 100644
--- a/tests/functional/lib/bash/test_header
+++ b/tests/functional/lib/bash/test_header
@@ -701,7 +701,7 @@ reftest() {
     run_ok "${TEST_NAME}-validate" cylc validate "${SUITE_NAME}"
     if [[ -n "${ABORT_ON_TASK_FAIL:-}" ]]; then
         suite_run_ok "${TEST_NAME}-run" \
-            cylc run --reference-test --debug --no-detach --fragile "${SUITE_NAME}"
+            cylc run --reference-test --debug --no-detach --abort-if-any-task-fails "${SUITE_NAME}"
     else
         suite_run_ok "${TEST_NAME}-run" \
             cylc run --reference-test --debug --no-detach "${SUITE_NAME}"
diff --git a/tests/functional/message-triggers/02-action.t b/tests/functional/message-triggers/02-action.t
index 8f3adfebf04..e83721e18e2 100644
--- a/tests/functional/message-triggers/02-action.t
+++ b/tests/functional/message-triggers/02-action.t
@@ -29,7 +29,7 @@ run_ok "${TEST_NAME}" cylc validate "${SUITE_NAME}"
 
 # The suite tests that two tasks suicide immediately on message triggers.
 TEST_NAME="${TEST_NAME_BASE}-run"
-suite_run_ok "${TEST_NAME}" cylc run --no-detach --fragile "${SUITE_NAME}"
+suite_run_ok "${TEST_NAME}" cylc run --no-detach --abort-if-any-task-fails "${SUITE_NAME}"
 
 # Check that final task pool indicates bar and baz ran
 # TODO: some final null task pool tests would be better on task_states table!
diff --git a/tests/functional/restart/25-hold-suite.t b/tests/functional/restart/25-hold-suite.t
index 2904be02f6e..9d52c115078 100755
--- a/tests/functional/restart/25-hold-suite.t
+++ b/tests/functional/restart/25-hold-suite.t
@@ -22,7 +22,7 @@ install_suite "${TEST_NAME_BASE}" "${TEST_NAME_BASE}"
 
 run_ok "${TEST_NAME_BASE}-validate" cylc validate "${SUITE_NAME}"
 suite_run_ok "${TEST_NAME_BASE}-run" \
-    cylc run "${SUITE_NAME}" --debug --no-detach --fragile
+    cylc run "${SUITE_NAME}" --debug --no-detach --abort-if-any-task-fails
 
 sqlite3 "${SUITE_RUN_DIR}/log/db" \
     'SELECT value FROM suite_params WHERE key=="is_held"' >'suite-is-held.out'
diff --git a/tests/functional/restart/33-simulation.t b/tests/functional/restart/33-simulation.t
index 003801f9882..10283196cb4 100644
--- a/tests/functional/restart/33-simulation.t
+++ b/tests/functional/restart/33-simulation.t
@@ -35,13 +35,13 @@ __FLOW_CONFIG__
 
 run_ok "${TEST_NAME_BASE}-validate" cylc validate "${SUITE_NAME}"
 suite_run_ok "${TEST_NAME_BASE}-run" \
-    cylc run --no-detach --stop-point=2019 --mode=simulation --fragile "${SUITE_NAME}"
+    cylc run --no-detach --stop-point=2019 --mode=simulation --abort-if-any-task-fails "${SUITE_NAME}"
 # Force a waiting task into a running task
 sqlite3 "${HOME}/cylc-run/${SUITE_NAME}/.service/db" \
     'UPDATE task_states SET status="running" WHERE name=="t1" AND cycle=="2019"'
 sqlite3 "${HOME}/cylc-run/${SUITE_NAME}/.service/db" \
     'UPDATE task_pool SET status="running" WHERE name=="t1" AND cycle=="2019"'
 suite_run_ok "${TEST_NAME_BASE}-restart" \
-    cylc restart --debug --no-detach --until=2020 --mode=simulation --fragile "${SUITE_NAME}"
+    cylc restart --debug --no-detach --until=2020 --mode=simulation --abort-if-any-task-fails "${SUITE_NAME}"
 purge_suite "${SUITE_NAME}"
 exit
diff --git a/tests/functional/restart/43-auto-restart-force-override-normal.t b/tests/functional/restart/43-auto-restart-force-override-normal.t
index 513ef812c3f..00239813d78 100644
--- a/tests/functional/restart/43-auto-restart-force-override-normal.t
+++ b/tests/functional/restart/43-auto-restart-force-override-normal.t
@@ -52,7 +52,7 @@ ${BASE_GLOBAL_CONFIG}
 set_test_number 7
 #-------------------------------------------------------------------------------
 # run suite
-cylc run "${SUITE_NAME}" --fragile
+cylc run "${SUITE_NAME}" --abort-if-any-task-fails
 poll_suite_running
 sleep 1
 FILE=$(cylc cat-log "${SUITE_NAME}" -m p |xargs readlink -f)
diff --git a/tests/functional/rnd/02-lib-python-in-job.t b/tests/functional/rnd/02-lib-python-in-job.t
index a66b2a2cb09..8d6e99e0386 100644
--- a/tests/functional/rnd/02-lib-python-in-job.t
+++ b/tests/functional/rnd/02-lib-python-in-job.t
@@ -26,6 +26,6 @@ TEST_NAME="${TEST_NAME_BASE}-validate"
 run_ok "${TEST_NAME}" cylc validate "${SUITE_NAME}"
 #-------------------------------------------------------------------------------
 TEST_NAME="${TEST_NAME_BASE}-run"
-suite_run_ok "${TEST_NAME}" cylc run --no-detach --fragile "${SUITE_NAME}"
+suite_run_ok "${TEST_NAME}" cylc run --no-detach --abort-if-any-task-fails "${SUITE_NAME}"
 #-------------------------------------------------------------------------------
 purge_suite "${SUITE_NAME}"
diff --git a/tests/functional/shutdown/12-bad-port-file-check.t b/tests/functional/shutdown/12-bad-port-file-check.t
index 0ca255e5e04..50152b9eed0 100755
--- a/tests/functional/shutdown/12-bad-port-file-check.t
+++ b/tests/functional/shutdown/12-bad-port-file-check.t
@@ -35,7 +35,7 @@ install_suite "${TEST_NAME_BASE}" "${TEST_NAME_BASE}"
 run_ok "${TEST_NAME_BASE}-validate" cylc validate ${OPT_SET} "${SUITE_NAME}"
 # shellcheck disable=SC2086
 suite_run_fail "${TEST_NAME_BASE}-run" \
-    cylc run --no-detach --fragile ${OPT_SET} "${SUITE_NAME}"
+    cylc run --no-detach --abort-if-any-task-fails ${OPT_SET} "${SUITE_NAME}"
 SRVD="$RUN_DIR/${SUITE_NAME}/.service"
 LOGD="$RUN_DIR/${SUITE_NAME}/log"
 grep_ok \
diff --git a/tests/functional/shutdown/13-no-port-file-check.t b/tests/functional/shutdown/13-no-port-file-check.t
index d0d6b179a79..e28230d611f 100755
--- a/tests/functional/shutdown/13-no-port-file-check.t
+++ b/tests/functional/shutdown/13-no-port-file-check.t
@@ -34,7 +34,7 @@ install_suite "${TEST_NAME_BASE}" "${TEST_NAME_BASE}"
 run_ok "${TEST_NAME_BASE}-validate" cylc validate ${OPT_SET} "${SUITE_NAME}"
 # shellcheck disable=SC2086
 suite_run_fail "${TEST_NAME_BASE}-run" \
-    cylc run --no-detach --fragile ${OPT_SET} "${SUITE_NAME}"
+    cylc run --no-detach --abort-if-any-task-fails ${OPT_SET} "${SUITE_NAME}"
 SRVD="$RUN_DIR/${SUITE_NAME}/.service"
 LOGD="$RUN_DIR/${SUITE_NAME}/log"
 grep_ok \
diff --git a/tests/functional/shutdown/14-no-dir-check.t b/tests/functional/shutdown/14-no-dir-check.t
index 62e7ffa2192..55d8d404206 100755
--- a/tests/functional/shutdown/14-no-dir-check.t
+++ b/tests/functional/shutdown/14-no-dir-check.t
@@ -35,7 +35,7 @@ SYM_SUITE_NAME="${SUITE_NAME}-sym"
 ln -s "$(basename "${SUITE_NAME}")" "${SYM_SUITE_RUND}"
 # shellcheck disable=SC2086
 suite_run_fail "${TEST_NAME_BASE}-run" \
-    cylc run --no-detach --fragile ${OPT_SET} "${SYM_SUITE_NAME}"
+    cylc run --no-detach --abort-if-any-task-fails ${OPT_SET} "${SYM_SUITE_NAME}"
 # Possible failure modes:
 # - health check detects missing run directory
 # - DB housekeeping cannot access DB because run directory missing