hdevtools 0.1.8.0-1build2 (amd64 binary) in ubuntu focal

 hdevtools is a backend for text editor plugins, to allow for things such as
 syntax and type checking of Haskell code, and retrieving type information, all
 directly from within your text editor.
 .
 The advantage that hdevtools has over ghc-mod is that it runs silently
 in a persistent background process, and therefore is able to keeps all of your
 Haskell modules and dependent libraries loaded in memory. This way, when you
 change only a single source file, only it needs to be reloaded and rechecked,
 instead of having to reload everything.
 .
 This makes hdevtools very fast for checking syntax and type errors (runs
 just as fast as the ":reload" command in GHCi).
 .
 In fact, syntax and type checking is so fast, that you can safely enable auto
 checking on every save. Even for huge projects, checking is nearly instant.
 .
 In addition to checking Haskell source code for errors, `hdevtools` has tools
 for getting info about identifiers, and getting type information for snippets
 of code.