Stack Overflow when updating files

I have updated to the newest version

Hugo Static Site Generator v0.64.0/extended darwin/amd64 BuildDate: unknown

and now when running as local server I always get a stack overflow when I update a file

Change detected, rebuilding site.
2020-02-07 21:55:36.222 +0100
Source changed “/Users/peter/5volts/v2/content/projects/toy.md”: WRITE
runtime: goroutine stack exceeds 1000000000-byte limit
fatal error: stack overflow

runtime stack:
runtime.throw(0x5923a6a, 0xe)
/usr/local/Cellar/go/1.13.7/libexec/src/runtime/panic.go:774 +0x72
runtime.newstack()
/usr/local/Cellar/go/1.13.7/libexec/src/runtime/stack.go:1046 +0x6e9
runtime.morestack()
/usr/local/Cellar/go/1.13.7/libexec/src/runtime/asm_amd64.s:449 +0x8f

You have a infinite recursion in one of your templates. Hard to tell without seeing your full project.

I did not make any changes. The crash did not occur with .60 . Also if there is a recursion why has it an effect only when I modify a file. A Recursion would crash the server immediately when I start hugo not only when I modify one of the content files

Checked the site with the theme I was using and updated my copy to the newest version. And now the problem has gone. In case this happens again, how do you find the culprit respectively the “looping” template? I have no clue how this could happen.