FTBFS with mysql 8: my_global.h: No such file or directory

After this one is fixed, there are other 3 classes of errors:
- mysql init functions (there are 3)
- mysql_options, when {my_,}load_defaults isn't found
- my_bool is gone

This bug was fixed in the package net-snmp - 5.7.3+dfsg-5ubuntu1

---------------
net-snmp (5.7.3+dfsg-5ubuntu1) disco; urgency=medium

  * Merge with Debian unstable. Remaining changes:
    - Add apport hook.
      + d/control: add dh-apport to Build-Depends
      + d/rules: install the apport hook via debhelper
      + d/source.apport: apport hook
    - d/p/0001-swinst_apt.c-Fix-indexing-of-hrSWInstalledTable-to-s.patch:
      set first hrSWInstalledIndex to 1 to follow RFC 2790 (LP #1314760)
  * Drop:
    - SECURITY UPDATE: DoS via NULL pointer exception
      + debian/patches/CVE-2018-18065.patch: fix logic in
        agent/helpers/table.c.
      + CVE-2018-18065
      [Fixed in 5.7.3+dfsg-4]
    - d/p/my_load_defaults: use my_load_defaults instead of the
      libmysqlclient-internal load_defaults (LP #1565003). Thanks to Lars
      Tangvald.
      [Replaced by a more complete patch]
    - debian/rules: Fix calculation of UPSTREAM_VERSION and COMPAT_VERSION.
      [No more needed since 5.7.3+dfsg-5]
  * Added:
    - d/p/snmptrapd_mysql_init: drop this patch. The first part fixes builds
      with newer mariadb, which Ubuntu doesn't use, and the second part is
      an unrelated change which we are fixing in another patch (see #1814254
      for details).
    - d/p/0001-Link-libnetsnmptrapd-against-MYSQL_LIBS.patch: Link
      libnetsnmptrapd against MYSQL_LIBS. Thanks to Adam
      Williamson <email address hidden>. (Closes: #886221, LP: #1814254)
    - Fix build with mysql-8 (LP: #1814270):
      + d/p/mysql8-replace-bool.patch: newer mysql dropped my_bool, use char
        instead.
      + d/p/my-load-defaults.patch: properly detect (and use)
        my_load_defaults(). This replaces the previous
        my_load_defaults patch.
      + d/p/mysql8-headers.patch: detect if my_global.h and my_sys.h are
        available
      + d/p/mysql-init.patch: handle the various mysql init functions
      + d/p/mysql-options.patch: use mysql_options if no {my_,}load_defaults
        was found.

net-snmp (5.7.3+dfsg-5) unstable; urgency=medium

  * Use debhelper macros for shlibs Closes: #912685
  * Relocate snmp.conf to libsnmp-base Closes: #914657

net-snmp (5.7.3+dfsg-4) unstable; urgency=medium

  [ Craig Small ]
  * Use correct snmpwalk args in snmpcheck Closes: #898197
  * Remove user only on purge Closes: #911216

  [ Ondřej Nový ]
  * d/copyright: Use https protocol in Format field
  * d/control: Removing redundant Priority field in binary package
  * d/changelog: Remove trailing whitespaces
  * d/control: Remove trailing whitespaces
  * d/watch: Use https protocol

  [ Salvatore Bonaccorso ]
  * snmpd crashes when receiving a GetNext PDU with multiple Varbinds
    (CVE-2018-18065) (Closes: #910638)

net-snmp (5.7.3+dfsg-3) unstable; urgency=medium

  * Compile perl module after library Closes: #894626

net-snmp (5.7.3+dfsg-2) unstable; urgency=medium

  [ Craig Small ]
  * New maintainer Closes: #835654
  * Imported old NMU diff Closes: #851343, #852479
  * Change VCS urls to salsa
  * Update to standards 4.1.3 - no change
  * Update to debhelper version 11
  * Remove empty copyright file for libsnmp30
  * snmp.prerm - remove killall
  * snm...