To get help when using pkgsrc, the definitive source is this document, the pkgsrc guide. If you don't find anything here, there are alternatives:
	The built-in pkgsrc help, which is available after bootstrapping
	pkgsrc. Run bmake help topic=… to get
	help for any topic, such as a variable name like
	BUILD_DEFS, a make target like
	do-build, a missing C or C++ function like
	strcasecmp or any other topic.
The available help topics are listed in Appendix E, Help topics.
	To see the value of a single variable, run bmake
	show-var VARNAME=X.
	To see the values of the most common variables, run
	bmake show-all. These variables are grouped by
	topic. To see the variables for a single topic, run
	bmake
	show-all-topic, for example
	bmake show-all-fetch.
The pkgsrc-users mailing list, to which you can subscribe and then ask your questions.
The #pkgsrc IRC channel, which is accessible via a web browser or by using a specialized chat program such as XChat. Pick any user name and join the channel #pkgsrc.