What font did I use?
So, I opened an old project that I created with gimp to see what font
I was using so I can match it.
No luck with the font tool... I Installed the text-info script,
checked the info provided by it and it's wrong.
How do I find out what font I used? Why doesn't the font tool remember
this? How does gimp render the font and not know what font it is?
If you saved your image in xcf format and don't merge or flatten the layers that contain the text strings then the information about font, point size etc. should be preserved. If you select the Text tool and left-click on the text it should show the information. I have just tried this. I had two strings in different fonts and point sizes and the expected information is shown when I reopen the file.
If you have saved the file in a raster format (for example jpg, tif, bmp etc) then the information about the text will have been discarded.