add instructions for creating bottles

Author: tmcdonell

BOTTLES.md

@@ -0,0 +1,42 @@
+# Bottles
+
+General instructions for writing formula: https://docs.brew.sh/Formula-Cookbook
+
+## GitHub
+
+GitHub allows attaching up to 2GB to a release, so we can use this as the host
+for the bottles.
+
+Example for llvm-10 release
+
+ * Commit llvm-10.rb and add a new tag v10.0.0
+
+ * brew install --build-bottle [--debug --verbose] ./Formula/llvm-10.rb
+
+ * brew bottle --json --force-core-tap --root-url https://github.com/llvm-hs/homebrew-llvm/releases/download/v10.0.0 ./Formula/llvm-10.rb
+
+ * edit llvm-10.rb to add the bottle information and commit
+
+ * The bottle likely has an incorrect name; if it contains a double-dash it
+   should be changed to a single dash:
+     llvm-10--10.0.0.mojave.bottle.tar.gz  ➜  llvm-10-10.0.0.mojave.bottle.tar.gz
+
+ * Go to https://github.com/llvm-hs/homebrew-llvm/releases and edit tag v10.0.0.
+   Attach the binary .bottle
+
+
+## Bintray
+
+Bintray is the default host used by Homebrew, but limits binary files to 250MB,
+which is not large enough for us.
+
+https://jonathanchang.org/blog/maintain-your-own-homebrew-repository-with-binary-bottles/
+
+Set environment variables `HOMEBREW_BINTRAY_USER` and `HOMEBREW_BINTRAY_KEY`
+(from bintray.com -> Edit Profile -> API Key)
+
+> brew test-bot --root-url=https://bintray.com/tmcdonell/bottles-llvm --bintray-org=BINTRAY_USER --tap=llvm-hs/llvm llvm-hs/homebrew-llvm/llvm-9
+> brew test-bot --ci-upload --git-name=USERNAME --git-email=EMAIL --bintray-org=BINTRAY_USER --root-url=https://bintray.com/tmcdonell/bottles-llvm
+
+Go to the package on bintray.com and hit "Publish".
+