auto_reset is one of several commands documented at http://www.purl.org/tcl/home/man/tcl8.5/TclCmd/library.htm

It destroys all the information cached by auto_execok and auto_load. This information will be re-read from disk the next time it is needed. Auto_reset also deletes any procedures listed in the auto-load index, so that fresh copies of them will be loaded the next time that they're used.

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