Adding a variant to an existing homebrew formula? -

i'd modify dtc formula build specialized version of dtc used beaglebone black (and other device-tree arm boards). problem multi-fold. dtc formula provides bottled versions, , installed 1.4.0. want install version comes newer sources, not absolute latest, , applies patch available elsewhere. can build manually on os x, don't know best way make available in homebrew.

i'd make variant. either entirely separate formula, or within current formula can selected command-line parameter. i'm not well-versed enough in brew know how best this.

i tried creating new formula called "dtc-dyn" doesn't dashes in name.

i'd make bottle, others' convenience, seems more complicated.

i tried modifying current dtc , removing bottle stuff, modifying url, version, , adding system steps. of operations fail (that seem work when run original build script):

def install     git_sha = "f6dbc6ca9618391e4f30c415a0a09b7af35f7647"      system "git checkout master -f"     system "git pull"     system "git checkout #{git_sha} -b #{git_sha}-build"     system "git pull --no-edit https://github.com/pantoniou/dtc dt-overlays5"     system "make clean"     system "make all" end 

sadly, doesn't work:

$ brew install dtc ==> cloning git://git.kernel.org/pub/scm/utils/dtc/dtc.git updating /library/caches/homebrew/dtc--git ==> checking out branch master ==> git checkout master -f ==> git pull ==> git checkout f6dbc6ca9618391e4f30c415a0a09b7af35f7647 -b f6dbc6ca9618391e4f30c415a0a09b7af35f7647-build 2015-09-21 00:22:37 -0700  git checkout f6dbc6ca9618391e4f30c415a0a09b7af35f7647 -b f6dbc6ca9618391e4f30c415a0a09b7af35f7647-build  fatal: reference not tree: f6dbc6ca9618391e4f30c415a0a09b7af35f7647  read this: https://git.io/brew-troubleshooting 

the original script can found here.

anyway, what's best way approach this? think kind of with-option, based on of example scripts, i'm not sure how avoid bottle business. thanks!

second approach

okay, after more doc reading , experimenting, i'm trying this:

class dtc < formula   desc "device tree compiler"   homepage "http://www.devicetree.org/"   url "https://mirrors.kernel.org/debian/pool/main/d/device-tree-compiler/device-tree-compiler_1.4.0+dfsg.orig.tar.gz"   mirror "https://mirrors.ocf.berkeley.edu/debian/pool/main/d/device-tree-compiler/device-tree-compiler_1.4.0+dfsg.orig.tar.gz"   sha256 "f5f9a1aea478ee6dbcece8907fd4551058fe72fc2c2a7be972e3d0b7eec4fa43"   version "1.4.0"    option "with-symbols", "add symbols/fixup support (-@ option)."    bottle…    if build.with? "symbols"     url "http://git.kernel.org/pub/scm/utils/dtc/dtc.git", :revision => "f6dbc6ca9618391e4f30c415a0a09b7af35f7647"     system "git", "pull", "--no-edit", "https://github.com/pantoniou/dtc", "dt-overlays5"   end    def install     system "make"     system "make", "destdir=#{prefix}", "prefix=", "install"     mv lib/"libfdt.dylib.1", lib/"libfdt.1.dylib"   end end 

unfortunately, git pull fails because before cloning git repo, , it's not in right directory. first considered patch do…, wasn't clear how apply patch via git pull. tried this:

  if build.with? "symbols"     url "http://git.kernel.org/pub/scm/utils/dtc/dtc.git", :revision => "f6dbc6ca9618391e4f30c415a0a09b7af35f7647"     patch         system "git", "pull", "--no-edit", "https://github.com/pantoniou/dtc", "dt-overlays5"     end   end 

but still tries git pull before cloning repo , cding it.