Fix conflict test node termination

On Windows, if a process is killed after it is dead, it returns `true`
for `was_killed`. Instead, check if the process is running before killing
it.

Also make the section where processes are running as short as possible,
and include context for both processes in every error.

zebra-test/src/command.rs

@@ -354,7 +354,8 @@ impl<T> TestChild<T> {
             .unwrap_or(false)
     }
 
-    fn is_running(&mut self) -> bool {
+    /// Is this process currently running?
+    pub fn is_running(&mut self) -> bool {
         matches!(self.child.try_wait(), Ok(None))
     }
 }

zebrad/tests/acceptance.rs

@@ -32,7 +32,10 @@ use zebra_chain::{
 };
 use zebra_network::constants::PORT_IN_USE_ERROR;
 use zebra_state::constants::LOCK_FILE_ERROR;
-use zebra_test::{command::TestDirExt, prelude::*};
+use zebra_test::{
+    command::{ContextFrom, TestDirExt},
+    prelude::*,
+};
 use zebrad::config::ZebradConfig;
 
 /// The amount of time we wait after launching `zebrad`.
@@ -1226,24 +1229,38 @@ where
     // In node1 we want to check for the success regex
     // If there are any errors, we also want to print the node2 output.
     let output1 = node1.wait_with_output();
-    let (output1, node2) = node2.kill_on_error(output1)?;
-    let res1 = output1.stdout_contains(first_stdout_regex);
-    let (_, node2) = node2.kill_on_error(res1)?;
-    let res1 = output1
-        .assert_was_killed()
-        .wrap_err("Possible port conflict. Are there other acceptance tests running?");
-    let (_, mut node2) = node2.kill_on_error(res1)?;
+    let (output1, mut node2) = node2.kill_on_error(output1)?;
 
     // node2 should have panicked due to a conflict. Kill it here
     // anyway, so it doesn't outlive the test on error.
-    let _ = node2.kill();
+    if node2.is_running() {
+        use color_eyre::eyre::eyre;
+        return node2
+            .kill_on_error::<(), _>(Err(eyre!("conflicted node2 did not panic")))
+            .context_from(&output1)
+            .map(|_| ());
+    }
+    // Now we're sure both nodes are dead, and we have both their outputs
+    let output2 = node2.wait_with_output().context_from(&output1)?;
+
+    // Look for the success regex
+    output1
+        .stdout_contains(first_stdout_regex)
+        .context_from(&output2)?;
+    use color_eyre::Help;
+    output1
+        .assert_was_killed()
+        .warning("Possible port conflict. Are there other acceptance tests running?")
+        .context_from(&output2)?;
 
     // In the second node we look for the conflict regex
-    let output2 = node2.wait_with_output()?;
-    output2.stderr_contains(second_stderr_regex)?;
+    output2
+        .stderr_contains(second_stderr_regex)
+        .context_from(&output1)?;
     output2
         .assert_was_not_killed()
-        .wrap_err("Possible port conflict. Are there other acceptance tests running?")?;
+        .warning("Possible port conflict. Are there other acceptance tests running?")
+        .context_from(&output1)?;
 
     Ok(())
 }