File library/utils/log.tcl
The use of ::pluglog::attributes is bound to <Configure>.
The bug: the script held in ::pluglog::attributes(all) evaluates winfo width at an early <Configure> event, and returns the result 1 (1 pixel): this gives a negative value -9 for the tab position which raises an error at startup.
The fix: in attributes(all), set a minimum value of 1 for the tab position. This avoids non-positive values which would raise an bgerror. Nonsense positive values are overwritten at the next <Configure> event.
Patch also increases log from 500 to 1000 lines, so that complete startup log can be inspected.