Created attachment 295294 [details]
build.log.xz

Personally I try to avoid gedit usage for reading files because it's really much slower than less for doing the same tasks and also eats a lot of resources.

Try to read the attached file as-is (even keeping it compressed)
1. First scenario:
$ less build.log.xz -> it's instant for me, then, I simply press "/mktm" to search that string and it reports me instantly that it doesn't exist

2. Second scenarion:
- Click on the file, it's opened by file-roller and I click on the file, file-rollers choosed gedit to open it and... it takes multiple seconds to load full file. Once it's loaded, it also takes time to search the same string

Thanks for your help. I am running 3.14 but I have always seen this then, it's not a regression I think