Add local::lib to the cpan logging.

Trying to work out why the perl code doesn't work, I've added some
extra logging which might help on the docker CI runs.

perl-env-setup

@@ -350,8 +350,10 @@ sed -E "s/^#.*//; /^ *$/d;" "${tmpinput}" \
 
 
 # Ensure that our environment is set up properly
+echo "local::lib configuration" > "${log_file}"
+
 mkdir -p "${environment}"
-eval "$(SHELL=/bin/bash perl -f -M"local::lib=${environment}" 2> /dev/null)"
+eval "$(SHELL=/bin/bash perl -f -M"local::lib=${environment}" 2>> "${log_file}" | tee -a "${log_file}")"
 if [ $? != 0 ] ; then
     echo "Failed to create local::lib environment"
     exit 1
@@ -368,7 +370,7 @@ while [[ "$environment_name" == 'perllib' ||
 done
 
 
-echo "CPAN output" > "${log_file}"
+echo "CPAN output" >> "${log_file}"
 
 # Ensure that we have a version of CPAN
 if ! check_module App::cpanminus 2>> "${log_file}" ; then