I have checked libkrb5.so and libkrb5support.so and done objdump -t. There is no function auth_userokay() in these libs, so there is a failure in config process. Who knows what is wrong with krb5?
I have upgrade dovecot version from 2.3.4 to 2.3.6.1. I aslo have enabled the feature GASSPI support for dovecot. Now it can be compiled without error.
I have checked the config log again. It can pass the configuration without krb5 support, like old version of dovecote.
configure:24598: result: no
configure:24626: checking for krb5-config
configure:24654: result: NO
configure:24914: error: Can't build with GSSAPI support: krb5-config not found
In old version, it exits from configuration with error. This new version can continue. so I can't confirm that GSSAPI can be supported in dovecot package.
I have upgraded the version of openssl to 1.1.1b because we want to support mips-r6.