problem with a variable in pdfinfo, probably something obvious

[Mike Marchywka]

I'm trying to include bib info in the pdf file in a machine readable format
and it mostly works. For example, 

( my script that just wraps an call to exiftool or whatever it is called ),

exifutil -list covid19.pdf | grep X-bib
X-bib-title                     : On the age distribution of SARS-Cov-2 Patients
X-bib-author                    : Mike J Marchywka
X-bib-type                      : TECHREPORT
X-bib-name                      : marchywka-MJM-2020-002
X-bib-number                    : MJM-2020-002
X-bib-institution               : not institutionalized, independent
X-bib-address                   :  306 Charles Cox , Canton GA 30115
X-bib-date                      : June 17, 2020
X-bib-version                   :  0.00 June 17, 2020 NOT public NOTES
X-bib-day                       : 11
X-bib-month                     : 05
X-bib-year                      : 2020
X-bib-author 1email             : marchywka at hotmail.com
X-bib-contact                   : marchywka at hotmail.com
X-bib-author 1id                : orcid.org/0000-0001-9237-455X
X-bib-pages                     :  covid19.lastpage
X-bib-filename                  : covid19

Except you may notice that the X-bib-pages contains a thing that was supposed to evaluate.

I use these definitions,

\newcommand{\mjmaddbib}[2]{\hypersetup{ pdfinfo={ x-bib-#1 = {#2}}}\mjmsummabib{#1}{#2}}
\newcommand{\mjmaddbibonly}[2]{\hypersetup{ pdfinfo={ x-bib-#1 = {#2}}}}
\newcommand{\mjmaddbibe}[2]{\hypersetup{ pdfinfo= x-bib-#1 = #2}}

And then in the text, the offending entry seems to ignore the "input" thing, 

\newcommand{\mjmemail}{marchywka at hotmail.com}
\mjmaddbib{title}{\mjmtitle}
\mjmaddbib{author}{\mjmauthor}
\mjmaddbib{type}{TECHREPORT}
\mjmaddbib{name}{marchywka-\mjmtrno}
\mjmaddbib{number}{\mjmtrno}
%\mjmaddbib{version}{\mjmversion}
\mjmaddbib{institution}{not institutionalized, independent }
\mjmaddbib{address}{ 306 Charles Cox , Canton GA 30115}
\mjmaddbib{date}{\today}
\mjmaddbib{version}{\mjmversion \today   \mjmstatus}
\mjmaddbib{day}{\mjmbibday}
\mjmaddbib{month}{\mjmbibmo}
\mjmaddbib{year}{\mjmbibyear}
\mjmaddbib{author1email}{\mjmemail}
\mjmaddbib{contact}{\mjmemail}
\mjmaddbib{author1id}{orcid.org/0000-0001-9237-455X}
\mjmaddbib{pages}{ \input{\mjmbasename.last_page}}
\mjmaddbib{filename}{\mjmbasename}

I'm storing the last page in a file for several reasons but why is input ignored here?

This gives the expected output, 

%   PAGES =         \{6\},
  PAGES =         \{ \input{\mjmbasename.last_page} \},

  CONTACT =       \{marchywka at hotmail.com\},



Thanks.

note new address
 Mike Marchywka 306 Charles Cox Drive Canton, GA 30115
 2295 Collinworth  Drive Marietta GA 30062.  formerly 487 Salem Woods Drive Marietta GA 30067 404-788-1216 (C)<- leave message 989-348-4796 (P)<- emergency