Add scripts to build for x86_64 linux too

Makefile

@@ -18,16 +18,42 @@ install: build-release
 	$(MAKE) sign-release
 	install target/release/rqbit "$(HOME)/bin/"
 
-@PHONY: release-all
-release-all:
+@PHONY: release-macos-universal
+release-macos-universal:
 	cargo build --target aarch64-apple-darwin --release
 	cargo build --target x86_64-apple-darwin --release
-	# brew install mingw-w64 for this to work
+	lipo \
+		./target/aarch64-apple-darwin/release/rqbit \
+		./target/x86_64-apple-darwin/release/rqbit \
+		-create \
+		-output ./target/x86_64-apple-darwin/release/rqbit-osx-universal
+
+@PHONY: release-windows
+release-windows:
+	# prereqs:
+	# brew install mingw-w64
 	cargo build --target x86_64-pc-windows-gnu --release
 
+@PHONY: release-linux
+release-linux:
+    # prereqs:
+    # brew tap messense/macos-cross-toolchains
+	# brew install x86_64-unknown-linux-gnu
+	# features are so that we don't need to cross-compile openssl
+	export CC_x86_64_unknown_linux_gnu=x86_64-unknown-linux-gnu-gcc && \
+	export CXX_x86_64_unknown_linux_gnu=x86_64-unknown-linux-gnu-g++ && \
+	export AR_x86_64_unknown_linux_gnu=x86_64-unknown-linux-gnu-ar && \
+	export CARGO_TARGET_X86_64_UNKNOWN_LINUX_GNU_LINKER=x86_64-unknown-linux-gnu-gcc && \
+	cargo build --release --target=x86_64-unknown-linux-gnu --no-default-features \
+		--features=sha1-rust,rust-tls
+
+
+@PHONY: release-all
+release-all: release-windows release-linux release-macos-universal
 	rm -rf /tmp/rqbit-release
 	mkdir -p /tmp/rqbit-release
-	lipo ./target/aarch64-apple-darwin/release/rqbit ./target/x86_64-apple-darwin/release/rqbit -create -output /tmp/rqbit-release/rqbit-osx-universal
 	cp ./target/x86_64-pc-windows-gnu/release/rqbit.exe /tmp/rqbit-release
+	cp ./target/x86_64-apple-darwin/release/rqbit-osx-universal /tmp/rqbit-release
+	cp ./target/x86_64-unknown-linux-gnu/release/rqbit /tmp/rqbit-release/rqbit-linux-x86_64
 
 	echo "The release was built in /tmp/rqbit-release"