libcrypto was not found in the pkg-config search path

[Alexis Praga]

Hi,

After an upgrade in the upstream version of the port, I can no longer compile 
it using poudriere. Resulting error message is :

Package libcrypto was not found in the pkg-config search path.
Perhaps you should add the directory containing `libcrypto.pc'
to the PKG_CONFIG_PATH environment variable
Package 'libcrypto', required by 'virtual:world', not found
CC: ['cc'] (13, 0)The package libcrypto was not found on your system

The previous version still build fine in poudriere. Any pointer on how to solve 
that ?
I've posted on the forums but got no satisfactory answer.

Thanks in advance,

Alexis