diff -Naur parallel-20220622.orig/Makefile.am parallel-20220622/Makefile.am

--- parallel-20220622.orig/Makefile.am	2022-06-22 09:06:29.000000000 +0300

+++ parallel-20220622/Makefile.am	2022-06-27 19:50:07.937507813 +0300

@@ -167,12 +167,12 @@

 	cd parallel-$(YYYYMMDD) && \

 	./configure && make -j && sudo make -j install

-zshcompletiondir=${datarootdir}/zsh/site-functions

+bashcompletiondir=$(DESTDIR)${datarootdir}/bash-completion/completions

+zshcompletiondir=$(DESTDIR)${datarootdir}/zsh/site-functions

 zshcompletion=${zshcompletiondir}/_parallel

 install-data-hook:

-	mkdir -p ${datarootdir}/bash-completion/completions

-	mkdir -p ${zshcompletiondir}

-	parallel --shell-completion bash > ${datarootdir}/bash-completion/completions/parallel

+	mkdir -p ${bashcompletiondir} ${zshcompletiondir}

+	src/parallel --shell-completion bash > ${bashcompletiondir}/parallel

 	echo '#compdef parallel' > ${zshcompletion}

 	echo '(( $$+functions[_comp_parallel] )) ||' >> ${zshcompletion}

 	echo '  eval "$$(parallel --shell-completion auto)" &&' >> ${zshcompletion}