doxygen2man: Add option to read copyright line from the header file

[chrissie-c]

This should help make builds reproducible.

I tried various methods of getting the date, using 'git' is no use as
it could be run from a tarball, using the file date doesn't work either
so this seems a reasonable compromise.

[bmwiedemann]

This change fixed the copyright and then I noticed another embedded date issue:

@@ -1,5 +1,5 @@
 .\"  Automatically generated man page, do not edit
-.TH QBUTIL.H 3 2020-09-07 "LIBQB" "libqb Programmer's Manual"
+.TH QBUTIL.H 3 2035-10-11 "LIBQB" "libqb Programmer's Manual"
 .SH NAME

[fabbione]

I like the approach, but then please use update-copyright.sh to update all files in the git tree.

[fabbione]

Also, I assume that we will need to change knet to use this new feature as well?

[chrissie-c]

@bmwiedemann good point. I'll look into that today. Thanks.

[bmwiedemann]

One option is to use $SOURCE_DATE_EPOCH - there are code snippets available, too.

[chrissie-c]

@bmwiedemann OK this addition patch seems to work for me, any chance you could test it on your system please?

If it works for you, do you need a new release or are the patches enough for the moment?

[bmwiedemann]

commit 4ea13bb made it reproducible in our openSUSE environment where we have $SOURCE_DATE_EPOCH set, but the git codepath looked a bit wrong to me with %at instead of %ct and with the extra $Format: in there.

[bmwiedemann]

do you need a new release or are the patches enough for the moment

patches are enough as reproducible-builds is a long-term project and I expect there will be a new release in the next months.

[chrissie-c]

I just copied the code from knet ;-)
But %ct makes sense