build(goreleaser): do not use mainnet to determine brew keg type

fixes #1191

Signed-off-by: Artur Troian <troian.ap@gmail.com>

Makefile

@@ -26,6 +26,9 @@ GIT_HEAD_COMMIT_LONG  := $(shell git log -1 --format='%H')
 GIT_HEAD_COMMIT_SHORT := $(shell git rev-parse --short HEAD)
 GIT_HEAD_ABBREV       := $(shell git rev-parse --abbrev-ref HEAD)
 
+GORELEASER_TAG       ?= $(shell git describe --tags --abbrev=0)
+GORELEASER_IS_PREREL ?= $(shell $(ROOT_DIR)/script/is_prerelease.sh "$(GORELEASER_TAG)")
+
 # BUILD_TAGS are for builds withing this makefile
 # GORELEASER_BUILD_TAGS are for goreleaser only
 # Setting mainnet flag based on env value
@@ -34,17 +37,20 @@ ifeq ($(MAINNET),true)
 	BUILD_MAINNET=mainnet
 	BUILD_TAGS=osusergo,netgo,ledger,mainnet,static_build
 	GORELEASER_BUILD_TAGS=$(BUILD_TAGS)
-	GORELEASER_HOMEBREW_NAME=akash
-	GORELEASER_HOMEBREW_CUSTOM=
 else
 	BUILD_TAGS=osusergo,netgo,ledger,static_build
 	GORELEASER_BUILD_TAGS=$(BUILD_TAGS),testnet
+
+endif
+
+ifeq ($(GORELEASER_IS_PREREL),false)
+	GORELEASER_HOMEBREW_NAME=akash
+	GORELEASER_HOMEBREW_CUSTOM=
+else
 	GORELEASER_HOMEBREW_NAME="akash-edge"
 	GORELEASER_HOMEBREW_CUSTOM=keg_only :unneeded, \"This is testnet release. Run brew install ovrclk/tap/akash to install mainnet version\"
 endif
 
-GORELEASER_TAG     ?= $(shell git describe --tags --abbrev=0)
-
 GORELEASER_FLAGS    = -tags="$(GORELEASER_BUILD_TAGS)"
 GORELEASER_LD_FLAGS = -s -w -X github.com/cosmos/cosmos-sdk/version.Name=akash \
 -X github.com/cosmos/cosmos-sdk/version.AppName=akash \

script/is_prerelease.sh

@@ -0,0 +1,12 @@
+#!/usr/bin/env bash
+
+# in akash even minor part of the tag indicates release belongs to the MAINNET
+# using it as scripts simplifies debugging as well as portability
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" >/dev/null 2>&1 && pwd)"
+
+if [[ $# -ne 1 ]]; then
+	echo "illegal number of parameters"
+	exit 1
+fi
+
+[[ -n $("${SCRIPT_DIR}"/semver.sh get prerel "$1") ]] && echo true || echo false