pkg/55110: www/curl: curl-7.69.1 fails to build due to circulur dependency

[mj%mjturner.net@localhost]

>Number:         55110
>Category:       pkg
>Synopsis:       www/curl: curl-7.69.1 fails to build due to circulur dependency
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    pkg-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Mar 26 10:00:03 +0000 2020
>Originator:     Michael-John Turner
>Release:        
>Organization:
>Environment:
Darwin <redacted> 18.7.0 Darwin Kernel Version 18.7.0: Thu Jan 23 06:52:12 PST 2020; root:xnu-4903.278.25~1/RELEASE_X86_64 x86_64
>Description:
After a fresh bootstrap of HEAD, building www/curl fails with the following error message:
...
ERROR: This package has set PKG_FAIL_REASON:
ERROR: Circular dependency detected
...

It's caused by www/curl depending on www/nghttp2, which depends on
net/libcares, which depends on devel/cmake, which depends on www/curl.

I've set this as priority 'high' as many packages depend on devel/cmake (which also has a circular dependency on www/curl).
>How-To-Repeat:
1. Ensure the pkgsrc tree is a recent checkout of the HEAD branch.
2. Change to www/curl
3. Attempt to build and install it

The build will fail with a circular dependency error.
>Fix: