To get help when developing 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 tech-pkg 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.