Skip user texmf for a particular package

Question

I have a couple of packages (luaotfload being one of them) for which I make use of the bleeding edge development version which has not been uploaded to CTAN yet. Now, this version can live quite nicely in my user texmf tree, but when placed there the flavor of TeX being used (LuaTex for this particular package, but the question is not specific to that flavor) will always find that bleeding edge version first and use it. On occasion, however, I have a document for which I want to go back to the stable version which is available on CTAN (and thus in my TeXLive managed texmf tree). Is there a way to tell the TeX engine not to look in the user texmf tree when looking for a particular package (I cannot simply skip the user texmf tree for all packages as I have some personal ones there which I use in nearly ever document)?

Alternatively, if I were to setup an "experimental" texmf tree (and place the bleeding edge package there) is there a way to instruct the TeX engine to look in that tree before looking in the usual places? Bonus points for a solution that can be controlled on a package by package basis, though I'm usually either using all the latest stuff, or only CTAN released stuff with a particular file.

Answer 1

This is a partial answer (because a fully general answer is probably "No".)

For packages without dependencies residing in your local texmf folder, you can specify the full path of the package in the \usepackage command. This will generate a warning about the package name not corresponding, but this can be safely ignored.

For example, \usepackage{/usr/local/texlive/2016/texmf-dist/tex/latex/foo} will load the distribution version of foo, and ignore a locally installed foo.

While this approach works for simple packages, it can very quickly break if package dependencies are involved, since any package or code loaded by that package will still be drawn from the local texmf tree. So in your particular case of luaotfload it probably won't work.

For an answer to the second part of your question (how to set up a bleeding edge texmf tree) see the following question:

• How to properly install two parallel version of the same package in TeX Live?