No, I meant to have everything in one line. That way, setting of PERL5LIB is valid for this particular invocation of perl only and does not clobber the current value of PERL5LIB (if any) for the rest of your shell session (if exported).

$: TEST=this    #-- your shell might need to 'export' explicitly
$: echo $TEST
this
$: TEST=that eval 'echo $TEST'
that
$: echo $TEST
this
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Setting PERL5LIB the way you did, would keep the setting for the rest of your shell session. You might consider to set it in your shells configuration (.bashrc, .profile, etc.) if required.

I am not sure, if I understood your last question.

I think it will still take the one already installed and not the one I cloned.

No, with path-to-your-local-directory, I meant the .../lib directory of your cloned installation. When in doubt try

PERL5LIB=<as-needed> perl -MDevel::Cover=-coverage,none  -e 'print "$D
+evel::Cover::VERSION <--- HERE!\n"'
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and see if the VERSION is as expected (Devel::Cover might print that anyways in its header message).