Refer to the catted file toward the end of https://builds.sr.ht/~tristan957/job/77959 on the third to last line of file where you will see ],. The last element in an array cannot end in a comma unless you support JSON 5.
I uploaded the file manually without the JSON error, and it worked fine.
For some reason, this is no longer happening in the latest builds. I am going to leave the issue open in the case someone wants to confirm that the issue was fixed. I am pulling from annotatec master, so maybe it got fixed unknowingly because a commit has been published.