mandb -p deleting "obsolete" Windows cat directories

[Brian Inglis <Brian dot Inglis at SystematicSw dot ab dot ca>]

Recently loaded up a bunch of man pages for other systems ("man -m SYSTEM") for
use across installs under /proc/cygdrive/c/usr/local/share/man/...

To make these usable I added short symlinks in those directories, added those to
/etc/man_db.conf (attached) with associated catpaths, then ran mandb -p
(--no-purge), which took a long time.

I was surprised when I looked at the log (attached, with lots of man directory
indexing stripped), that mandb -p decide to scan my C drive and perform the
undocumented action of removing Windows localization cat directories that it
considers obsolete e.g.
"...
Removing obsolete cat directory /proc/cygdrive/c/Windows/en-US...
"
which is kind of worrisome, especially when the complete path is not shown!

Question is why does mandb scan the whole drive, think Windows cat directories
are its property, delete them while running with -p, and suggestions for how I
can stop mandb doing that, including configuration or system changes, or
approaches to mandb patches, I can make to do that?

I have renamed /etc/postinstall/zp_man-db.sh temporarily to avoid future surprises.

--------------------
MANPATH is the result of a profile script developed over the years to set up all
useful man directories on various systems, without duplicates, depending on
whether they are accessible from each system at login.

$ echo $MANPATH
/usr/local/man:/usr/man:/usr/ssl/man:/usr/share/sendmail/man:/usr/share/texmf-dist/doc/man:/proc/cygdrive/c/usr/local/share/man:/proc/cygdrive/c/usr/local/cygwin32/usr/share/man:/proc/cygdrive/c/usr/local/ubuntu/usr/share/man:/proc/cygdrive/c/usr/local/ast/src/lib/libast/man:/proc/cygdrive/c/usr/local/ast/arch/cygwin.i386/man:

-- 
Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada

Attachment: man_db.conf
Description: Text document

Attachment: mandb.log
Description: Text document

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