Add a patch to permit to override usemime via environment - pkgsrc-localpatches - leot's pkgsrc LOCALPATCHES
 (HTM) hg clone https://bitbucket.org/iamleot/pkgsrc-localpatches
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 (DIR) changeset 15b6ebeea60b0ca57995d8c573ed2dae277d9212
 (DIR) parent ca342459b76896b379a78013831ae8123fc6542a
 (HTM) Author: Leonardo Taccari <iamleot@gmail.com>
       Date:   Thu,  6 Jun 2019 23:47:28 
       
       Add a patch to permit to override usemime via environment
       
       Diffstat:
        mail/mhpgp/patch-mhsign |  16 ++++++++++++++++
        1 files changed, 16 insertions(+), 0 deletions(-)
       ---
       diff -r ca342459b768 -r 15b6ebeea60b mail/mhpgp/patch-mhsign
       --- /dev/null   Thu Jan 01 00:00:00 1970 +0000
       +++ b/mail/mhpgp/patch-mhsign   Thu Jun 06 23:47:28 2019 +0200
       @@ -0,0 +1,16 @@
       +$NetBSD$
       +
       +Permit to override usemime option from the environment.
       +
       +--- mhsign.orig        2007-05-30 15:12:22.000000000 +0000
       ++++ mhsign
       +@@ -42,7 +42,8 @@ USAGE="mhsign [-rRdemb] messagefile"
       + 
       + # defaults
       + mimefixbody=y
       +-usemime=
       ++#usemime=
       ++## allow to be defined in environment.
       + function=sign
       + 
       + while getopts rdRemb op