From 97def3c10449a7f0347a36dd0ffff49b88805fbf Mon Sep 17 00:00:00 2001
From: Mike McQuaid <mike@mikemcquaid.com>
Date: Thu, 26 Jan 2023 11:06:53 +0000
Subject: [PATCH] install: better error when using API and --HEAD.

- Tell people what to do to resolve this
- Tweak the instruction ordering to be consistent elsewhere
---
 Library/Homebrew/brew.rb              | 2 +-
 Library/Homebrew/dev-cmd/edit.rb      | 2 +-
 Library/Homebrew/formula_installer.rb | 2 +-
 Library/Homebrew/install.rb           | 9 +++++++++
 4 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/Library/Homebrew/brew.rb b/Library/Homebrew/brew.rb
index 06db7fe9f4..a279381289 100644
--- a/Library/Homebrew/brew.rb
+++ b/Library/Homebrew/brew.rb
@@ -96,8 +96,8 @@ begin
       odie <<~EOS
         This command cannot be run while Homebrew/homebrew-core is untapped and
         HOMEBREW_NO_INSTALL_FROM_API is unset! To resolve please run:
-          brew tap Homebrew/core
           export HOMEBREW_NO_INSTALL_FROM_API=1
+          brew tap Homebrew/core
         and retry this command.
       EOS
     end
diff --git a/Library/Homebrew/dev-cmd/edit.rb b/Library/Homebrew/dev-cmd/edit.rb
index 38dc15b0f4..445ee48681 100644
--- a/Library/Homebrew/dev-cmd/edit.rb
+++ b/Library/Homebrew/dev-cmd/edit.rb
@@ -65,8 +65,8 @@ module Homebrew
           <<~EOS
             #{not_exist_message}
             This is expected with HOMEBREW_NO_INSTALL_FROM_API unset! To resolve please run:
-              brew tap Homebrew/core
               export HOMEBREW_NO_INSTALL_FROM_API=1
+              brew tap Homebrew/core
             and retry this command.
           EOS
         elsif args.cask?
diff --git a/Library/Homebrew/formula_installer.rb b/Library/Homebrew/formula_installer.rb
index 16662f76d2..cc4266afb3 100644
--- a/Library/Homebrew/formula_installer.rb
+++ b/Library/Homebrew/formula_installer.rb
@@ -1185,8 +1185,8 @@ class FormulaInstaller
       odie <<~EOS
         Unable to build #{formula.name} from source while Homebrew/homebrew-core is
         untapped and HOMEBREW_NO_INSTALL_FROM_API is unset! To resolve please run:
-          brew tap Homebrew/core
           export HOMEBREW_NO_INSTALL_FROM_API=1
+          brew tap Homebrew/core
         and retry.
       EOS
     else
diff --git a/Library/Homebrew/install.rb b/Library/Homebrew/install.rb
index 86e0f7c5b6..62d1a594f7 100644
--- a/Library/Homebrew/install.rb
+++ b/Library/Homebrew/install.rb
@@ -113,6 +113,15 @@ module Homebrew
         EOS
       end
 
+      if head && Homebrew::EnvConfig.install_from_api?
+        raise UsageError, <<~EOS
+          --HEAD is not supported with HOMEBREW_NO_INSTALL_FROM_API unset! To resolve please run:
+            export HOMEBREW_NO_INSTALL_FROM_API=1
+            brew tap Homebrew/core
+          and retry this command.
+        EOS
+      end
+
       # --HEAD, fail with no head defined
       odie "No head is defined for #{f.full_name}" if head && f.head.nil?