fix Android build on MacOS due to lack of OS var

changes:
- Drop use of /dev/stderr, doesn't work on MacOS
- Use uname -s instead of $OS which was removed
- Remove leading whitespace that fucks with Nix
- Check if `/etc/os-release` exists before reading it

Signed-off-by: Jakub Sokołowski <jakub@status.im>

Makefile

@@ -48,7 +48,7 @@ export TARGET ?= $(TARGET_OS)
 endif
 
 # Useful for checking if we are on NixOS
-OS_NAME := $(shell awk -F= '/^NAME/{print $2}' /etc/os-release)
+OS_NAME := $(shell [ -f /etc/os-release ] && awk -F= '/^NAME/{print $2}' /etc/os-release)
 
 # Useful for Andoird release builds
 TMP_BUILD_NUMBER := $(shell ./scripts/version/gen_build_no.sh | cut -c1-10)

scripts/generate-keystore.sh

@@ -31,7 +31,7 @@ KEYSTORE_PATH=$(env_var_or_gradle_prop 'KEYSTORE_PATH')
 KEYSTORE_PATH=${KEYSTORE_PATH/#\~/$HOME}
 
 if [[ -e "${KEYSTORE_PATH}" ]]; then
-    echo -e "${YLW}Keystore file already exists:${RST} ${KEYSTORE_PATH}" > /dev/stderr
+    echo -e "${YLW}Keystore file already exists:${RST} ${KEYSTORE_PATH}" >&2
     echo "${KEYSTORE_PATH}"
     exit 0
 fi
@@ -39,7 +39,7 @@ fi
 KEYSTORE_DIR=$(dirname "${KEYSTORE_PATH}")
 [[ -d $KEYSTORE_DIR ]] || mkdir -p $KEYSTORE_DIR
 
-echo -e "${GRN}Generating keystore...${RST}" > /dev/stderr
+echo -e "${GRN}Generating keystore...${RST}" >&2
 
 keytool -genkey -v \
     -keyalg RSA \

scripts/release-android.sh

@@ -46,7 +46,7 @@ nixOpts+=(
   "--argstr" "secrets-file" "${SECRETS_FILE_PATH}"
 )
 
-if [[ "$OS" =~ Darwin ]]; then
+if [[ "$(uname -s)" =~ Darwin ]]; then
   # Start a watchman instance if not started already and store its socket path.
   # In order to get access to the right versions of watchman and jq,
   # we start an ad-hoc nix-shell that imports the packages from nix/nixpkgs-bootstrap.