From 4d5cca8ef248c64e5ba8bb81e13fdf72ea8a61fc Mon Sep 17 00:00:00 2001
From: "Aleksey @soar Smyrnov" <i@soar.name>
Date: Mon, 7 Jan 2019 13:49:53 +0300
Subject: [PATCH] Comments for commit extraction

Requested in https://github.com/ethereum/go-ethereum/pull/18315
---
 internal/build/env.go | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/internal/build/env.go b/internal/build/env.go
index bfa054c36c..9f7b18673f 100644
--- a/internal/build/env.go
+++ b/internal/build/env.go
@@ -88,6 +88,9 @@ func LocalEnv() Environment {
 	if splits := strings.Split(head, " "); len(splits) == 2 {
 		head = splits[1]
 	} else {
+		// In this case we are in "detached head" state
+		// see: https://git-scm.com/docs/git-checkout#_detached_head
+		// Additional check required to verify, that file contains commit hash
 		commitRe, _ := regexp.Compile("^([0-9a-f]{40})$")
 		if commit := commitRe.FindString(head); commit != "" && env.Commit == "" {
 			env.Commit = commit