How to manually install a package for LuaLaTeX

I used to have an old version of a package (pgfplots v 1.9) and I manually installed a later version (v 1.12) complete with new documentation. pdflatex indeed compiles with the newest version while LuaLaTeX is “stuck” with the older one.

Here is an example of the behaviour:

documentclass[border=5pt]{standalone}
usepackage{tikz}
usepackage{pgfplots}
pgfplotsset{compat=1.12} % this line creates problems
begin{document}
begin{tikzpicture}
  begin{axis}
    addplot {x^2};
  end{axis}
end{tikzpicture}
end{document}

If the file is compiled with pdflatex, the compiler says:

[...] Package pgfplots notification ‘compat/show suggested
version=true’: document has been generated with the most recent
feature set (pgfplotsset{compat=1.12}). [...]

and everything goes right, while LuaLaTeX gives me the following message and then stops without producing any page of output:

[...] ! Package pgfkeys Error: Choice ’1.12′ unknown in choice key
‘/pgfplots/compat/anchors’. I am going to ignore this key. [...]

However, if I do not require to use the latest version (1.12), the compilation goes smoothly for both engines. The compiler’s message is in both cases:

[...] Package pgfplots Warning: running in backwards compatibility
mode (unsuitable tick labels; missing features). Consider writing
pgfplotsset{compat=1.9} into your preamble. [...]

So the question is: How can I manually install/make available a package for compilations (also) with LuaLaTeX?

I work with TeXLive in a GNU/Linux system. I know this is not the recommended way to proceed, but I do not have tlmgr.

Possibly related: How do I install an individual package on a Linux system?