Comment 9 for bug 1021815

I speak for Inkscape Portable as its developer and maintainer. Inkscape Portable is an officially supported build of Inkscape. I cannot speak of Inkscape itself and how it does it, but I agree that it certainly shouldn't require a long operation. How does the GIMP do it? Does it have a long delay?

Inkscape Portable keeps a clean TEMP directory; this means that the font cache is lost every time you run it. This is standard behaviour for PortableApps.com apps and is probably still desirable in this case as the font cache is going to be machine-dependant. (Would it use a stale/invalid font cache if you moved machines? I don't know. But that could be a worse problem than the slowness.)

If you wish to try it with leaving the font config behind on the host machine (so that it will only need to generate it once per machine you use), modify InkscapePortable\App\AppInfo\Launcher\InkscapePortable.ini: in the [Launch] section, add a line CleanTemp=false. You will need to do this for every new release, though, as I do not intend to change the behaviour. Note that setting CleanTemp=false will also have the effect of leaving anything else Inskcape puts in the TEMP directory behind, which could include personally identifiable information in rare cases.

There's also the option of adding [DirectoriesMove]:fontconfig=%TEMP%\fontconfig to InkscapePortable.ini; this would keep the fontconfig directory in InkscapePortable\Data\fontconfig. Before attempting anything like that, though, we'd need to verify its behaviour with switching machines. I don't believe it's likely to work well. At the best, I expect it would throw away the cache every time you tried to hit it on a new machine, and so it would only benefit you as long as you continued using it on the one machine. It's also possible that I/O performance could be a problem.