#2638: documentation.tex assume to be a specific location relative to Cactus root directory

Reporter: Roland Haas Status: new Milestone: Version: Type: bug Priority: minor Component:

Currently the LaTeX documentation files must include a relative path to `cactus.sty` like so:

``` \usepackage{../../../../doc/latex/cactus} ```

which, assuming the “typical” directory layout, accidentally works both when calling `pdflatex` directly (and manually) on the LaTeX input file in the source code location and via the various `-ThornDoc` and `-ThornGuide` make targets.

This is however fragile and fails if e.g. the thorn lives in a git repository of its own so that the directory layout is:

```text Cactus | +- repos | +- ThornRepo | +- doc | +- documenation.tex ```

rather than the expected

``` Cactus | +- repos | +- ArrRepo | +- Thorn | +- doc | +- documenation.tex ```

or (the initially envisioned one assumes):

``` Cactus | +- arrangements | +- ArrangeMent | +- Thorn | +- doc | +- documenation.tex ```

One way to handle this is to use conditionals to try both locations:

```tex \IfFileExists{../../../doc/latex/cactus.sty} % then {\usepackage{../../../doc/latex/cactus}} % else {\usepackage{../../../../doc/latex/cactus}} ```

which is somewhat cumbersome and only works for those two locations so must be adjusted for each thorn. Another, likely the officially suggested way, is to the `TEXINPUTS` such that `cactus.sty` is directly found. E.g. something like:

``` export TEXTIPUTS=$TOP/doc/latex/: ```

in the Makefile and then use `\usepackage{cactus}` in `documentation.tex`. This however means one can no longer run `pdflatex` directly on the LaTeX sources. There is, since TeX does not actually itself do the searching, no way to set `TEXINPUTS` or a similar thing in TeX files it seems.

`\IfFileExists` may rely on LuaTeX features (not sure) and one may even have to resort to pure TeX for say tex4ht to work ([https://tex.stackexchange.com/questions/98203/can-i-test-if-a-file-exists%5D...).

-- Ticket URL: https://bitbucket.org/einsteintoolkit/tickets/issues/2638/documentationtex-a...