I've pushed code to make as much as possible locale independent. Can't promise your plugins will work as expected, but the server should at least.
No offense, but Turkish locale is bloody ridiculous.
It would also appear that this is a regression based on either java or operating system upgrades.
I would seriously suggest you consider running your servers in English
@__0x277F - Issue is likely related due to the charset; I did take a look into this issue and did suggest another person with the issue to use the Jira to report it however they didn't; In that instance all of the decompiled files matched my own local copy; (something that was originally broken before https://hub.spigotmc.org/stash/projects/SPIGOT/repos/builddata/commits/da49b96b47c219f2284ec3f25939e223cf17665d); Looks like the locale issue is hitting further down the build process now;
Same error 
Log:
http://paste.md-5.net/dirugewuti.tex
Can you reproduce this with a cleaned BuildTools directory?