Running a pipeline job on a raspberry pi (buildpi1), the job fails to execute a simple 'sh' directive claiming the following syntax error:

durable_task_monitor_1.31_unix_32: Syntax error: "(" unexpected

Here's the Jenkinsfile:

Jenkinsfile.txt
 

Here's an excerpt from the console output:
[Pipeline] }[Pipeline] // stage[Pipeline] withEnv[Pipeline] {[Pipeline] stage[Pipeline]

{ (Hello)[Pipeline] echohello[Pipeline] sh/var/jenkins/caches/durable-task/durable_task_monitor_1.31_unix_32: 1: /var/jenkins/caches/durable-task/durable_task_monitor_1.31_unix_32: Syntax error: "(" unexpected process apparently never started in /var/jenkins/workspace/hello-pi_master@tmp/durable-8f36b150[Pipeline] }

[Pipeline] // stage[Pipeline] stage[Pipeline]

{ (Declarative: Post Actions)[Pipeline] echoFailure[Pipeline] }

[Pipeline] // stage[Pipeline] }[Pipeline] // withEnv[Pipeline] }[Pipeline] // node[Pipeline] End of PipelineERROR: script returned exit code -2
Finished: FAILURE
 

Here's the org.jenkinsci.plugins.durabletask logging:

 
Nov 05, 2019 12:25:17 PM org.jenkinsci.plugins.durabletask.executors.ContinuedTask$Scheduler canTake
FINER: ExecutorStepExecution.PlaceholderTask

{runId=hello-pi/master#3,label=armv7l_pi,context=CpsStepContext[3:node]:Owner[hello-pi/master/3:hello-pi/master #3|#3],cookie=null,auth=null}

 is not continued, so it would not block ExecutorStepExecution.PlaceholderTask

{runId=hello-pi/master#3,label=armv7l_pi,context=CpsStepContext[3:node]:Owner[hello-pi/master/3:hello-pi/master #3|#3],cookie=null,auth=null}

Nov 05, 2019 12:25:17 PM org.jenkinsci.plugins.durabletask.executors.ContinuedTask$Scheduler canTake
FINER: no reason to block ExecutorStepExecution.PlaceholderTask

{runId=hello-pi/master#3,label=armv7l_pi,context=CpsStepContext[3:node]:Owner[hello-pi/master/3:hello-pi/master #3|#3],cookie=null,auth=null}

Nov 05, 2019 12:25:17 PM org.jenkinsci.remoting.util.AnonymousClassWarnings warn
WARNING: Attempt to (de-)serialize anonymous class org.jenkinsci.plugins.gitclient.Git$1 in file:/Users/Shared/Jenkins/Home/plugins/git-client/WEB-INF/lib/git-client.jar; see: https://jenkins.io/redirect/serialization-of-anonymous-classes/
Nov 05, 2019 12:25:21 PM org.jenkinsci.remoting.util.AnonymousClassWarnings warn
WARNING: Attempt to (de-)serialize anonymous class org.jenkinsci.plugins.gitclient.RemoteGitImpl$CommandInvocationHandler$1 in file:/Users/Shared/Jenkins/Home/plugins/git-client/WEB-INF/lib/git-client.jar; see: https://jenkins.io/redirect/serialization-of-anonymous-classes/
Nov 05, 2019 12:25:24 PM org.jenkinsci.plugins.durabletask.BourneShellScript launchWithCookie
FINE: launching [/var/jenkins/caches/durable-task/durable_task_monitor_1.31_unix_32, -controldir=/var/jenkins/workspace/hello-pi_master@tmp/durable-1696d9b6, -result=/var/jenkins/workspace/hello-pi_master@tmp/durable-1696d9b6/jenkins-result.txt, -log=/var/jenkins/workspace/hello-pi_master@tmp/durable-1696d9b6/jenkins-log.txt, -cookiename=JENKINS_SERVER_COOKIE, -cookieval=durable-6f565f35441ab86a66f506894014f646, -script=/var/jenkins/workspace/hello-pi_master@tmp/durable-1696d9b6/script.sh, -shell=/bin/bash]
Nov 05, 2019 12:25:24 PM org.jenkinsci.plugins.durabletask.FileMonitoringTask$FileMonitoringController writeLog
FINE: remote transcoding charset: null
Nov 05, 2019 12:25:24 PM org.jenkinsci.plugins.durabletask.BourneShellScript$ShellController exitStatus
FINE: starting check in /var/jenkins/workspace/hello-pi_master@tmp/durable-1696d9b6
Nov 05, 2019 12:29:04 PM jenkins.branch.MultiBranchProject$BranchIndexing run
INFO: spatial_pi #20191105.122901 branch indexing action completed: SUCCESS in 3.8 sec
Nov 05, 2019 12:30:37 PM org.jenkinsci.plugins.workflow.job.WorkflowRun finish
INFO: hello-pi/master #3 completed: FAILURE
 

Here's the buildpi1 launch log:

SSHLauncher{host='buildpi1.local', port=22, credentialsId='34aaa861-6852-4df9-8534-a9ef1933d907', jvmOptions='-Dorg.jenkinsci.plugins.durabletask.BourneShellScript.LAUNCH_DIAGNOSTICS=true', javaPath='', prefixStartSlaveCmd='', suffixStartSlaveCmd='', launchTimeoutSeconds=210, maxNumRetries=10, retryWaitTime=15, sshHostKeyVerificationStrategy=hudson.plugins.sshslaves.verifiers.KnownHostsFileKeyVerificationStrategy, tcpNoDelay=true, trackCredentials=true}
[11/05/19 12:23:20] [SSH] Opening SSH connection to buildpi1.local:22.
[11/05/19 12:23:21] [SSH] SSH host key matches key in Known Hosts file. Connection will be allowed.
[11/05/19 12:23:21] [SSH] Authentication successful.
[11/05/19 12:23:21] [SSH] The remote user's environment is:
BASH=/bin/bash
BASHOPTS=checkwinsize:cmdhist:complete_fullquote:extquote:force_fignore:globasciiranges:hostcomplete:interactive_comments:progcomp:promptvars:sourcepath
BASH_ALIASES=()
BASH_ARGC=([0]="0")
BASH_ARGV=()
BASH_CMDS=()
BASH_EXECUTION_STRING=set
BASH_LINENO=()
BASH_SOURCE=()
BASH_VERSINFO=([0]="5" [1]="0" [2]="3" [3]="1" [4]="release" [5]="arm-unknown-linux-gnueabihf")
BASH_VERSION='5.0.3(1)-release'
DIRSTACK=()
EUID=1001
GROUPS=()
HOME=/home/build
HOSTNAME=buildpi1
HOSTTYPE=arm
IFS=$' \t\n'
LANG=en_GB.UTF-8
LOGNAME=build
MACHTYPE=arm-unknown-linux-gnueabihf
MAIL=/var/mail/build
OPTERR=1
OPTIND=1
OSTYPE=linux-gnueabihf
PATH=/usr/local/bin:/usr/bin:/bin:/usr/games
PIPESTATUS=([0]="0")
PPID=23344
PS4='+ '
PWD=/home/build
SHELL=/bin/bash
SHELLOPTS=braceexpand:hashall:interactive-comments
SHLVL=1
SSH_CLIENT='192.168.1.82 63259 22'
SSH_CONNECTION='192.168.1.82 63259 192.168.1.192 22'
TERM=dumb
UID=1001
USER=build
XDG_RUNTIME_DIR=/run/user/1001
XDG_SESSION_CLASS=user
XDG_SESSION_ID=c22
XDG_SESSION_TYPE=tty
_=']'
[11/05/19 12:23:21] [SSH] Checking java version of /var/jenkins/jdk/bin/java
Couldn't figure out the Java version of /var/jenkins/jdk/bin/java
bash: /var/jenkins/jdk/bin/java: No such file or directory

[11/05/19 12:23:21] [SSH] Checking java version of java
[11/05/19 12:23:22] [SSH] java -version returned 1.8.0_212.
[11/05/19 12:23:22] [SSH] Starting sftp client.
[11/05/19 12:23:22] [SSH] Copying latest remoting.jar...
Source agent hash is 388207AE638DEFCFB5229C655BCC5239. Installed agent hash is 388207AE638DEFCFB5229C655BCC5239
Verified agent jar. No update is necessary.
Expanded the channel window size to 4MB
[11/05/19 12:23:22] [SSH] Starting agent process: cd "/var/jenkins" && java -Dorg.jenkinsci.plugins.durabletask.BourneShellScript.LAUNCH_DIAGNOSTICS=true -jar remoting.jar -workDir /var/jenkins -jar-cache /var/jenkins/remoting/jarCache
Nov 05, 2019 8:23:23 PM org.jenkinsci.remoting.engine.WorkDirManager initializeWorkDir
INFO: Using /var/jenkins/remoting as a remoting work directory
Nov 05, 2019 8:23:23 PM org.jenkinsci.remoting.engine.WorkDirManager setupLogging
INFO: Both error and output logs will be printed to /var/jenkins/remoting
<===[JENKINS REMOTING CAPACITY]===>channel started
Remoting version: 3.33
This is a Unix agent
Evacuated stdout
Agent successfully connected and online
Nov 05, 2019 8:25:17 PM org.jenkinsci.remoting.util.AnonymousClassWarnings warn
WARNING: Attempt to (de-)serialize anonymous class org.jenkinsci.plugins.gitclient.Git$1; see: https://jenkins.io/redirect/serialization-of-anonymous-classes/
Nov 05, 2019 8:25:21 PM org.jenkinsci.remoting.util.AnonymousClassWarnings warn
WARNING: Attempt to (de-)serialize anonymous class org.jenkinsci.plugins.gitclient.RemoteGitImpl$CommandInvocationHandler$1; see: https://jenkins.io/redirect/serialization-of-anonymous-classes/