pg_restore error when using the --single-transaction: options c/--clean and -a/--data-only cannot be used together (even so the -a flag was not used)

Question

I met a strange PostgreSQL (v.13.8) on a Windows server 2019 machine today when trying to restore a custom dump file.

The following command worked:

pg_restore -d postgres://postgres@localhost:5432/postgres --no-owner --no-privileges --create --clean --role=<myuser> --if-exists inputfile.backup 2> inputfile.log

but by simply adding the --single-transaction option to the command line, it raised an error:

pg_restore -d postgres://postgres@localhost:5432/postgres --no-owner --no-privileges --single-transaction --create --clean --role=<myuser> --if-exists inputfile.backup 2> inputfile.log

But I can read this in the log file:

pg_restore: error : options « -c/--clean » and « -a/--data-only » cannot be used together.

I didn't even use the -a flag... This is strange, isn't it?
I've read through the pg_restore doc, especially the paragraph about the --single-transaction option but it doesn't say much about it, (for example about an underlying implicit -a flag):

--single-transaction

Execute the restore as a single transaction (that is, wrap the emitted commands in BEGIN/COMMIT). This ensures that either all the commands complete successfully, or no changes are applied. This option implies --exit-on-error.

Anyone can tell me what exactly is happening when using this option?

Answer 1

I don't know how you get the different language messages to be used.

But there is an obvious copy-and-paste mistake in the French translation file src/bin/pg_dump/po/fr.po:

#: pg_restore.c:338
#, c-format
msgid "options -C/--create and -1/--single-transaction cannot be used together"
msgstr "les options « -c/--clean » et « -a/--data-only » ne peuvent pas être utilisées ensemble"

Bug reported.