Workaround for removal of "." from @inc.

Starting in perl 5.26, the current directory "."
is now longer in @inc by default. This causes installation
to fail for lots of modules (especially those using Module::Install).
The PERL_USE_UNSAFE_INC environment variable let's us get the old
behavior until newer CPAN modules are available.

etc/install.sh

@@ -119,6 +119,9 @@ chmod 755 "$PINTO_CPANM_EXE"
 
 echo "Installing pinto into $PINTO_HOME"
 
+# Workaround for removal of "." from @INC in perl 5.26.0
+export PERL_USE_UNSAFE_INC=1
+
 "$PINTO_CPANM_EXE" --notest --quiet --mirror $PINTO_REPO_URL --mirror-only  \
       --local-lib-contained "$PINTO_HOME" --man-pages Pinto