Run tests sequentially

Since we share a tun device and routes, the tests do not support being
executed in parallel.

Cargo.toml

@@ -13,7 +13,8 @@ smoltcp = { version = "0.9", features = ["std"] }
 
 [dev-dependencies]
 ctor = "0.1"
-reqwest = { version = "0.11", features = ["blocking", "json"] }
 fork = "0.1"
+nix = { version = "0.26", features = ["process", "signal"] }
 prctl = "1.0"
-nix = { version = "0.26", features = ["process", "signal"] }
+reqwest = { version = "0.11", features = ["blocking", "json"] }
+serial_test = "1.0"

tests/proxy.rs

@@ -5,6 +5,7 @@ mod tests {
     use fork::Fork;
     use nix::sys::signal;
     use nix::unistd::Pid;
+    use serial_test::serial;
     use std::env;
     use std::io::BufRead;
     use std::net::{SocketAddr, ToSocketAddrs};
@@ -147,11 +148,13 @@ mod tests {
     }
 
     #[test]
+    #[serial]
     fn test_socks5() {
         run_test(|test| test.proxy_type == ProxyType::Socks5)
     }
 
     #[test]
+    #[serial]
     fn test_http() {
         run_test(|test| test.proxy_type == ProxyType::Http)
     }