(flow) sutherlander@cortex-vbox:share-bin$ ls
flow.cylc  share-src
(flow) sutherlander@cortex-vbox:share-bin$ cat share-src/bin/hello.sh 
#!/bin/bash

echo 'Hello! handler activated!'
touch ${CYLC_WORKFLOW_SHARE_DIR}/handler_activated

[meta]
    title = "Test calling a handler from share/bin"
[scheduling]
    cycling mode = integer
    initial cycle point = 1
    [[graph]]
        R1 = "foo => bar"
[runtime]
    [[root]]
        pre-script = sleep 10
        [[[events]]]
            handlers = hello.sh
            handler events = succeeded
    [[foo]]
        script = """
rm -rf ${CYLC_WORKFLOW_SHARE_DIR}/bin
cp -rf ${CYLC_WORKFLOW_RUN_DIR}/share-src/bin ${CYLC_WORKFLOW_SHARE_DIR}/
chmod 0755 ${CYLC_WORKFLOW_SHARE_DIR}/bin/*
"""
    [[bar]]
        script = """
if ! [[ -f ${CYLC_WORKFLOW_SHARE_DIR}/handler_activated ]]; then
    false
fi
"""