Jenkins Git plugin uses  /opt/freeware/bin/git which aborts with a shared library load issue. Root cause is the LIBPATH variable, which gets set internal by the slave and unfortunately exported to the job environment. I tried setting an empty LIBPATH in the slave config but with no avail.

Only workaround is to set a Jenkins Job parameter LIBPATH with empty value, which is odd.

I vote that the LIBPATH which gets exported to the job should have the original system value and it should not include the JVM environment of the slave.

I use Jenkins 2.375.2. In my case the original LIBPATH (/bin/sh forked by ssh) is just unset/blank. The slave (started with /opt/jdk11.0.16/bin/java) adds the following LIBPATH value and exports it to the job shell environment:
LIBPATH=/opt/jdk11.0.16/lib/server:/opt/jdk11.0.16/lib:/opt/jdk11.0.16/lib/jli:/opt/jdk11.0.16/../lib:/usr/lib 

The Git checkout aborted with following exception (copied from console):

[Pipeline] checkoutThe recommended git tool is: NONE
using credential Read-Only
Cloning the remote Git repository
Using no checkout clone with sparse checkout.
ERROR: Error cloning remote repo 'origin'
hudson.plugins.git.GitException: Could not init /WM/TESTSRV/testenv/wir_simple_install_uninstall
at org.jenkinsci.plugins.gitclient.CliGitAPIImpl$5.execute(CliGitAPIImpl.java:1049)
at org.jenkinsci.plugins.gitclient.CliGitAPIImpl$2.execute(CliGitAPIImpl.java:802)
at org.jenkinsci.plugins.gitclient.RemoteGitImpl$CommandInvocationHandler$GitCommandMasterToSlaveCallable.call(RemoteGitImpl.java:158)
at org.jenkinsci.plugins.gitclient.RemoteGitImpl$CommandInvocationHandler$GitCommandMasterToSlaveCallable.call(RemoteGitImpl.java:151)
at app//hudson.remoting.UserRequest.perform(UserRequest.java:211)
at app//hudson.remoting.UserRequest.perform(UserRequest.java:54)
at app//hudson.remoting.Request$2.run(Request.java:377)
at app//hudson.remoting.InterceptingExecutorService.lambda$wrap$0(InterceptingExecutorService.java:78)
at java.base@11.0.16.1/java.util.concurrent.FutureTask.run(FutureTask.java:264)
at java.base@11.0.16.1/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
at java.base@11.0.16.1/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
at java.base@11.0.16.1/java.lang.Thread.run(Thread.java:840)
Suppressed: hudson.remoting.Channel$CallSiteStackTrace: Remote call to wmadmin.aixwm6tm13
at hudson.remoting.Channel.attachCallSiteStackTrace(Channel.java:1784)
at hudson.remoting.UserRequest$ExceptionResponse.retrieve(UserRequest.java:356)
at hudson.remoting.Channel.call(Channel.java:1000)
at org.jenkinsci.plugins.gitclient.RemoteGitImpl$CommandInvocationHandler.execute(RemoteGitImpl.java:143)
at jdk.internal.reflect.GeneratedMethodAccessor1155.invoke(Unknown Source)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:566)
at org.jenkinsci.plugins.gitclient.RemoteGitImpl$CommandInvocationHandler.invoke(RemoteGitImpl.java:129)
at com.sun.proxy.$Proxy292.execute(Unknown Source)
at hudson.plugins.git.GitSCM.retrieveChanges(GitSCM.java:1226)
at hudson.plugins.git.GitSCM.checkout(GitSCM.java:1309)
at org.jenkinsci.plugins.workflow.steps.scm.SCMStep.checkout(SCMStep.java:129)
at org.jenkinsci.plugins.workflow.steps.scm.SCMStep$StepExecutionImpl.run(SCMStep.java:97)
at org.jenkinsci.plugins.workflow.steps.scm.SCMStep$StepExecutionImpl.run(SCMStep.java:84)
at org.jenkinsci.plugins.workflow.steps.SynchronousNonBlockingStepExecution.lambda$start$0(SynchronousNonBlockingStepExecution.java:47)
at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
at java.base/java.lang.Thread.run(Thread.java:829)
Caused by: hudson.plugins.git.GitException: Command "git init /WM/TESTSRV/testenv/wir_simple_install_uninstall" returned status code 255:
stdout:
stderr: exec(): 0509-036 Cannot load program git_64 because of the following errors:
0509-150 Dependent module /usr/lib/libiconv.a(libiconv.so.2) could not be loaded.
0509-152 Member libiconv.so.2 is not found in archive

at org.jenkinsci.plugins.gitclient.CliGitAPIImpl.launchCommandIn(CliGitAPIImpl.java:2734)
at org.jenkinsci.plugins.gitclient.CliGitAPIImpl.launchCommandIn(CliGitAPIImpl.java:2660)
at org.jenkinsci.plugins.gitclient.CliGitAPIImpl.launchCommandIn(CliGitAPIImpl.java:2656)
at org.jenkinsci.plugins.gitclient.CliGitAPIImpl.launchCommand(CliGitAPIImpl.java:1981)
at org.jenkinsci.plugins.gitclient.CliGitAPIImpl$5.execute(CliGitAPIImpl.java:1047)
... 11 more[Pipeline] }[Pipeline] // stage[Pipeline] }[Pipeline] // ws[Pipeline] }[Pipeline] // node[Pipeline] End of PipelineERROR: Error cloning remote repo 'origin'
Finished: FAILURE