Comment (by Roland Haas):

GetComponents supports some very limited replacement variables in the URL, AUTH_URL and REPO_PATH variables, namely it will take the <ARRANGEMENT>/<THORN> entry of each thorn and will assign <ARRANGEMENT> to $1 (ie the first thingy) and $2 will be set to <THORN> (ie the second component). More or less like Perl with do when one used a pattern m!([^/]*)/(.*)!.

There is also some magic in how REPO_PATH behaves depending on whether it does or does not contain a $1 or $2.

If it does contain a $1 or $2 then the relative path inside of the repository will be exactly as given by REPO_PATH (after variable expansion). If on the other hand no $1 or $2 is found, then the relative path in the repo is <REPOS_PATH>/<ARRANGEMENT>/<THORN>.

What needs to go into REPO_PATH thus hugely depends on the git repository layout. $2 often works nicely because people tend to put all thorns into the root of the git repo. .. is somewhat unusual.

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Ticket URL: https://bitbucket.org/einsteintoolkit/tickets/issues/2747/inclusion-of-sgrid-importer-in-einstein