add ability to specifiy commit ref

README.md

@@ -95,6 +95,10 @@ A package must be declared in the following format.
   -- Defaults to whatever the remote configured as their HEAD, which is usually "master".
   branch = "develop",
 
+  -- [string] Overrides the commit ref to target
+  -- Defaults to the latest commit on the current branch
+  commit = "e76cb03",
+
   -- [boolean] Prevents the package from being loaded.
   disable = true,
 

lua/dep.lua

@@ -78,6 +78,7 @@ local function register(spec, overrides)
   package.url = spec.url or package.url or ("https://github.com/" .. id .. ".git")
   package.branch = spec.branch or package.branch
   package.dir = base_dir .. package.name
+  package.commit = spec.commit
   package.pin = overrides.pin or spec.pin or package.pin
   package.enabled = not overrides.disable and not spec.disable and package.enabled
 
@@ -493,7 +494,7 @@ local function sync(package, cb)
         log_err(before)
         cb(err)
       else
-        proc.git_fetch(package.dir, "origin", package.branch or "HEAD", function(err, message)
+        local function continue(err, message)
           if err then
             log_err(message)
             cb(err)
@@ -519,18 +520,35 @@ local function sync(package, cb)
               end
             end)
           end
-        end)
+        end
+        if package.commit then
+          proc.git_checkout(package.dir, package.branch, package.commit, continue)
+        else
+          proc.git_fetch(package.dir, "origin", package.branch or "HEAD", continue)
+        end
       end
     end)
   else
     proc.git_clone(package.dir, package.url, package.branch, function(err, message)
       if err then
         logger:log("error", string.format("failed to install %s; reason: %s", package.id, message))
+      else
+        if package.commit then
+          proc.git_checkout(package.dir, package.branch, package.commit, function(err, message)
+            if err then
+              logger:log("error", string.format("failed to checkout %s; reason: %s", package.id, message))
             else
               package.exists = true
               mark_reconfigure(package)
               logger:log("install", string.format("installed %s", package.id))
             end
+          end)
+        else
+          package.exists = true
+          mark_reconfigure(package)
+          logger:log("install", string.format("installed %s", package.id))
+        end
+      end
 
       cb(err)
     end)

lua/dep/proc.lua

@@ -61,4 +61,14 @@ function proc.git_reset(dir, treeish, cb)
   proc.exec("git", args, dir, git_env, cb)
 end
 
+function proc.git_checkout(dir, branch, commit, cb)
+  local args = { "fetch", "--unshallow", "origin", branch }
+  proc.exec("git", args, dir, git_env, function(err, message)
+    cb(err, message)
+
+    args = { "checkout", commit }
+    proc.exec("git", args, dir, git_env, cb)
+  end)
+end
+
 return proc