The haskell-language-server (HLS) project is an implementation of a server (a "language server") for the Language Server Protocol (LSP). A language server talks to a client (typically an editor), which can ask the server to perform various operations, such as reporting errors or providing code completions. The advantage of this system is that clients and servers can interoperate more easily so long as they all speak the LSP protocol. In the case of HLS, that means that it can be used with many different editors, since editor support for the LSP protocol is now widespread.
Binary packages can be installed with the high-level tool pkgin (which can be installed with pkg_add) or pkg_add(1) (installed by default). The NetBSD packages collection is also designed to permit easy installation from source.
The pkg_admin audit command locates any installed package which has been mentioned in security advisories as having vulnerabilities.
Please note the vulnerabilities database might not be fully accurate, and not every bug is exploitable with every configuration.
Problem reports, updates or suggestions for this package should be reported with send-pr.