1 files changed, 16 insertions, 6 deletions

diff --git a/src/luarocks/build/command.lua b/src/luarocks/build/command.tl
index b0c4aa79..10f8bb94 100644
--- a/src/luarocks/build/command.lua
+++ b/src/luarocks/build/command.tl
@@ -1,23 +1,33 @@
 
+local type Build = require("luarocks.core.types.build").Build
+
 --- Build back-end for raw listing of commands in rockspec files.
-local command = {}
+local record command
+   record CommandBuild
+      is Build where self.type == "command"
+
+      build_command: string
+      install_command: string
+   end
+end
 
 local fs = require("luarocks.fs")
 local util = require("luarocks.util")
 local cfg = require("luarocks.core.cfg")
 
+local type Rockspec = require("luarocks.core.types.rockspec").Rockspec
+
 --- Driver function for the "command" build back-end.
 -- @param rockspec table: the loaded rockspec.
 -- @return boolean or (nil, string): true if no errors occurred,
 -- nil and an error message otherwise.
-function command.run(rockspec, not_install)
-   assert(rockspec:type() == "rockspec")
+function command.run(rockspec: Rockspec, not_install: boolean): boolean, string, string
 
-   local build = rockspec.build
+   local build = rockspec.build as command.CommandBuild
 
-   util.variable_substitutions(build, rockspec.variables)
+   util.variable_substitutions(build as {string: string}, rockspec.variables)
 
-   local env = {
+   local env: {string: string} = {
       CC = cfg.variables.CC,
       --LD = cfg.variables.LD,
       --CFLAGS = cfg.variables.CFLAGS,