building Dovecot in Debian 9

[KT Walrus]

I’m trying to build Dovecot 2.2.29.1 in a Docker container today and have the following error in ./configure:

checking for shadow.h... yes
checking for pam_start in -lpam... no
checking for auth_userokay... no
checking for mysql_config... mysql_config
checking for mysql_init in -lmysqlclient... no
configure: error: Can't build with MySQL support: libmysqlclient not found

#> find / -name libmysqlclient\*
/usr/share/doc/libmysqlclient20
/usr/share/lintian/overrides/libmysqlclient20
/usr/lib/x86_64-linux-gnu/libmysqlclient.so.20.3.5
/usr/lib/x86_64-linux-gnu/libmysqlclient.so.20
/var/lib/dpkg/info/libmysqlclient20:amd64.triggers
/var/lib/dpkg/info/libmysqlclient20:amd64.shlibs
/var/lib/dpkg/info/libmysqlclient20:amd64.list
/var/lib/dpkg/info/libmysqlclient20:amd64.md5sums

I have installed MySQL 5.7.18 Debian 9 packages (including the libmysqlclient-dev package) from the MySQL repo.

I’m not an expert, but is there a bug in the "./configure --prefix=/usr --sysconfdir=/etc --with-mysql”?

I’ve been building Dovecot with this Dockerfile using Ubuntu 16.04 for a while now without issue. Do I need some extra ./configure option to get it to find libmysqlclient.so.20?

Kevin