diff --git a/crates/cargo-test-support/src/lib.rs b/crates/cargo-test-support/src/lib.rs
index f12f935fa78..fbaa9dd0d9b 100644
--- a/crates/cargo-test-support/src/lib.rs
+++ b/crates/cargo-test-support/src/lib.rs
@@ -798,13 +798,17 @@ impl Execs {
         match res {
             Ok(out) => self.match_output(&out),
             Err(e) => {
-                let err = e.downcast_ref::<ProcessError>();
-                if let Some(&ProcessError {
-                    output: Some(ref out),
+                if let Some(ProcessError {
+                    stdout: Some(stdout),
+                    stderr: Some(stderr),
+                    code,
                     ..
-                }) = err
+                }) = e.downcast_ref::<ProcessError>()
                 {
-                    return self.match_output(out);
+                    return self
+                        .match_status(*code, stdout, stderr)
+                        .and(self.match_stdout(stdout, stderr))
+                        .and(self.match_stderr(stdout, stderr));
                 }
                 Err(format!("could not exec process {}: {:?}", process, e))
             }
@@ -813,119 +817,91 @@ impl Execs {
 
     fn match_output(&self, actual: &Output) -> MatchResult {
         self.verify_checks_output(actual);
-        self.match_status(actual)
-            .and(self.match_stdout(actual))
-            .and(self.match_stderr(actual))
+        self.match_status(actual.status.code(), &actual.stdout, &actual.stderr)
+            .and(self.match_stdout(&actual.stdout, &actual.stderr))
+            .and(self.match_stderr(&actual.stdout, &actual.stderr))
     }
 
-    fn match_status(&self, actual: &Output) -> MatchResult {
+    fn match_status(&self, code: Option<i32>, stdout: &[u8], stderr: &[u8]) -> MatchResult {
         match self.expect_exit_code {
             None => Ok(()),
-            Some(code) if actual.status.code() == Some(code) => Ok(()),
+            Some(expected) if code == Some(expected) => Ok(()),
             Some(_) => Err(format!(
-                "exited with {}\n--- stdout\n{}\n--- stderr\n{}",
-                actual.status,
-                String::from_utf8_lossy(&actual.stdout),
-                String::from_utf8_lossy(&actual.stderr)
+                "exited with {:?}\n--- stdout\n{}\n--- stderr\n{}",
+                code,
+                String::from_utf8_lossy(&stdout),
+                String::from_utf8_lossy(&stderr)
             )),
         }
     }
 
-    fn match_stdout(&self, actual: &Output) -> MatchResult {
+    fn match_stdout(&self, stdout: &[u8], stderr: &[u8]) -> MatchResult {
         self.match_std(
             self.expect_stdout.as_ref(),
-            &actual.stdout,
+            stdout,
             "stdout",
-            &actual.stderr,
+            stderr,
             MatchKind::Exact,
         )?;
         for expect in self.expect_stdout_contains.iter() {
-            self.match_std(
-                Some(expect),
-                &actual.stdout,
-                "stdout",
-                &actual.stderr,
-                MatchKind::Partial,
-            )?;
+            self.match_std(Some(expect), stdout, "stdout", stderr, MatchKind::Partial)?;
         }
         for expect in self.expect_stderr_contains.iter() {
-            self.match_std(
-                Some(expect),
-                &actual.stderr,
-                "stderr",
-                &actual.stdout,
-                MatchKind::Partial,
-            )?;
+            self.match_std(Some(expect), stderr, "stderr", stdout, MatchKind::Partial)?;
         }
         for &(ref expect, number) in self.expect_stdout_contains_n.iter() {
             self.match_std(
                 Some(expect),
-                &actual.stdout,
+                stdout,
                 "stdout",
-                &actual.stderr,
+                stderr,
                 MatchKind::PartialN(number),
             )?;
         }
         for expect in self.expect_stdout_not_contains.iter() {
             self.match_std(
                 Some(expect),
-                &actual.stdout,
+                stdout,
                 "stdout",
-                &actual.stderr,
+                stderr,
                 MatchKind::NotPresent,
             )?;
         }
         for expect in self.expect_stderr_not_contains.iter() {
             self.match_std(
                 Some(expect),
-                &actual.stderr,
+                stderr,
                 "stderr",
-                &actual.stdout,
+                stdout,
                 MatchKind::NotPresent,
             )?;
         }
         for expect in self.expect_stderr_unordered.iter() {
-            self.match_std(
-                Some(expect),
-                &actual.stderr,
-                "stderr",
-                &actual.stdout,
-                MatchKind::Unordered,
-            )?;
+            self.match_std(Some(expect), stderr, "stderr", stdout, MatchKind::Unordered)?;
         }
         for expect in self.expect_neither_contains.iter() {
             self.match_std(
                 Some(expect),
-                &actual.stdout,
+                stdout,
                 "stdout",
-                &actual.stdout,
+                stdout,
                 MatchKind::NotPresent,
             )?;
 
             self.match_std(
                 Some(expect),
-                &actual.stderr,
+                stderr,
                 "stderr",
-                &actual.stderr,
+                stderr,
                 MatchKind::NotPresent,
             )?;
         }
 
         for expect in self.expect_either_contains.iter() {
-            let match_std = self.match_std(
-                Some(expect),
-                &actual.stdout,
-                "stdout",
-                &actual.stdout,
-                MatchKind::Partial,
-            );
-            let match_err = self.match_std(
-                Some(expect),
-                &actual.stderr,
-                "stderr",
-                &actual.stderr,
-                MatchKind::Partial,
-            );
+            let match_std =
+                self.match_std(Some(expect), stdout, "stdout", stdout, MatchKind::Partial);
+            let match_err =
+                self.match_std(Some(expect), stderr, "stderr", stderr, MatchKind::Partial);
 
             if let (Err(_), Err(_)) = (match_std, match_err) {
                 return Err(format!(
@@ -938,12 +914,12 @@ impl Execs {
         }
 
         for (with, without) in self.expect_stderr_with_without.iter() {
-            self.match_with_without(&actual.stderr, with, without)?;
+            self.match_with_without(stderr, with, without)?;
         }
 
         if let Some(ref objects) = self.expect_json {
-            let stdout = str::from_utf8(&actual.stdout)
-                .map_err(|_| "stdout was not utf8 encoded".to_owned())?;
+            let stdout =
+                str::from_utf8(stdout).map_err(|_| "stdout was not utf8 encoded".to_owned())?;
             let lines = stdout
                 .lines()
                 .filter(|line| line.starts_with('{'))
@@ -962,8 +938,8 @@ impl Execs {
         }
 
         if !self.expect_json_contains_unordered.is_empty() {
-            let stdout = str::from_utf8(&actual.stdout)
-                .map_err(|_| "stdout was not utf8 encoded".to_owned())?;
+            let stdout =
+                str::from_utf8(stdout).map_err(|_| "stdout was not utf8 encoded".to_owned())?;
             let mut lines = stdout
                 .lines()
                 .filter(|line| line.starts_with('{'))
@@ -990,12 +966,12 @@ impl Execs {
         Ok(())
     }
 
-    fn match_stderr(&self, actual: &Output) -> MatchResult {
+    fn match_stderr(&self, stdout: &[u8], stderr: &[u8]) -> MatchResult {
         self.match_std(
             self.expect_stderr.as_ref(),
-            &actual.stderr,
+            stderr,
             "stderr",
-            &actual.stdout,
+            stdout,
             MatchKind::Exact,
         )
     }
diff --git a/src/bin/cargo/commands/bench.rs b/src/bin/cargo/commands/bench.rs
index 160ccd9abe8..79580862e1f 100644
--- a/src/bin/cargo/commands/bench.rs
+++ b/src/bin/cargo/commands/bench.rs
@@ -74,7 +74,7 @@ pub fn exec(config: &mut Config, args: &ArgMatches<'_>) -> CliResult {
     let err = ops::run_benches(&ws, &ops, &bench_args)?;
     match err {
         None => Ok(()),
-        Some(err) => Err(match err.exit.as_ref().and_then(|e| e.code()) {
+        Some(err) => Err(match err.code {
             Some(i) => CliError::new(anyhow::format_err!("bench failed"), i),
             None => CliError::new(err.into(), 101),
         }),
diff --git a/src/bin/cargo/commands/run.rs b/src/bin/cargo/commands/run.rs
index ed17e952b31..c8b711364d0 100644
--- a/src/bin/cargo/commands/run.rs
+++ b/src/bin/cargo/commands/run.rs
@@ -90,7 +90,7 @@ pub fn exec(config: &mut Config, args: &ArgMatches<'_>) -> CliResult {
 
         // If we never actually spawned the process then that sounds pretty
         // bad and we always want to forward that up.
-        let exit = match proc_err.exit {
+        let exit_code = match proc_err.code {
             Some(exit) => exit,
             None => return CliError::new(err, 101),
         };
@@ -98,7 +98,6 @@ pub fn exec(config: &mut Config, args: &ArgMatches<'_>) -> CliResult {
         // If `-q` was passed then we suppress extra error information about
         // a failed process, we assume the process itself printed out enough
         // information about why it failed so we don't do so as well
-        let exit_code = exit.code().unwrap_or(101);
         let is_quiet = config.shell().verbosity() == Verbosity::Quiet;
         if is_quiet {
             CliError::code(exit_code)
diff --git a/src/bin/cargo/commands/test.rs b/src/bin/cargo/commands/test.rs
index 04d4dce34fb..7e87afc8dcb 100644
--- a/src/bin/cargo/commands/test.rs
+++ b/src/bin/cargo/commands/test.rs
@@ -125,7 +125,7 @@ pub fn exec(config: &mut Config, args: &ArgMatches<'_>) -> CliResult {
         None => Ok(()),
         Some(err) => {
             let context = anyhow::format_err!("{}", err.hint(&ws, &ops.compile_opts));
-            let e = match err.exit.as_ref().and_then(|e| e.code()) {
+            let e = match err.code {
                 // Don't show "process didn't exit successfully" for simple errors.
                 Some(i) if errors::is_simple_exit_code(i) => CliError::new(context, i),
                 Some(i) => CliError::new(Error::from(err).context(context), i),
diff --git a/src/bin/cargo/main.rs b/src/bin/cargo/main.rs
index 64a465108a1..85b45a360ea 100644
--- a/src/bin/cargo/main.rs
+++ b/src/bin/cargo/main.rs
@@ -171,7 +171,7 @@ fn execute_external_subcommand(config: &Config, cmd: &str, args: &[&str]) -> Cli
     };
 
     if let Some(perr) = err.downcast_ref::<ProcessError>() {
-        if let Some(code) = perr.exit.as_ref().and_then(|c| c.code()) {
+        if let Some(code) = perr.code {
             return Err(CliError::code(code));
         }
     }
diff --git a/src/cargo/core/compiler/mod.rs b/src/cargo/core/compiler/mod.rs
index d2cd60b2c79..23c3f384f05 100644
--- a/src/cargo/core/compiler/mod.rs
+++ b/src/cargo/core/compiler/mod.rs
@@ -297,7 +297,7 @@ fn rustc(cx: &mut Context<'_, '_>, unit: &Unit, exec: &Arc<dyn Executor>) -> Car
             match err
                 .downcast_ref::<ProcessError>()
                 .as_ref()
-                .and_then(|perr| perr.exit.and_then(|e| e.code()))
+                .and_then(|perr| perr.code)
             {
                 Some(n) if errors::is_simple_exit_code(n) => VerboseError::new(err).into(),
                 _ => err,
diff --git a/src/cargo/util/errors.rs b/src/cargo/util/errors.rs
index acc301a5587..cf4ceb4bfdb 100644
--- a/src/cargo/util/errors.rs
+++ b/src/cargo/util/errors.rs
@@ -192,14 +192,25 @@ impl<'a> ::std::iter::FusedIterator for ManifestCauses<'a> {}
 pub struct ProcessError {
     /// A detailed description to show to the user why the process failed.
     pub desc: String,
+
     /// The exit status of the process.
     ///
-    /// This can be `None` if the process failed to launch (like process not found).
-    pub exit: Option<ExitStatus>,
-    /// The output from the process.
+    /// This can be `None` if the process failed to launch (like process not
+    /// found) or if the exit status wasn't a code but was instead something
+    /// like termination via a signal.
+    pub code: Option<i32>,
+
+    /// The stdout from the process.
+    ///
+    /// This can be `None` if the process failed to launch, or the output was
+    /// not captured.
+    pub stdout: Option<Vec<u8>>,
+
+    /// The stderr from the process.
     ///
-    /// This can be `None` if the process failed to launch, or the output was not captured.
-    pub output: Option<Output>,
+    /// This can be `None` if the process failed to launch, or the output was
+    /// not captured.
+    pub stderr: Option<Vec<u8>>,
 }
 
 impl fmt::Display for ProcessError {
@@ -218,7 +229,7 @@ impl std::error::Error for ProcessError {}
 pub struct CargoTestError {
     pub test: Test,
     pub desc: String,
-    pub exit: Option<ExitStatus>,
+    pub code: Option<i32>,
     pub causes: Vec<ProcessError>,
 }
 
@@ -254,7 +265,7 @@ impl CargoTestError {
         CargoTestError {
             test,
             desc,
-            exit: errors[0].exit,
+            code: errors[0].code,
             causes: errors,
         }
     }
@@ -359,20 +370,39 @@ pub fn process_error(
     output: Option<&Output>,
 ) -> ProcessError {
     let exit = match status {
-        Some(s) => status_to_string(s),
+        Some(s) => exit_status_to_string(s),
         None => "never executed".to_string(),
     };
-    let mut desc = format!("{} ({})", &msg, exit);
 
-    if let Some(out) = output {
-        match str::from_utf8(&out.stdout) {
+    process_error_raw(
+        msg,
+        status.and_then(|s| s.code()),
+        &exit,
+        output.map(|s| s.stdout.as_slice()),
+        output.map(|s| s.stderr.as_slice()),
+    )
+}
+
+pub fn process_error_raw(
+    msg: &str,
+    code: Option<i32>,
+    status: &str,
+    stdout: Option<&[u8]>,
+    stderr: Option<&[u8]>,
+) -> ProcessError {
+    let mut desc = format!("{} ({})", msg, status);
+
+    if let Some(out) = stdout {
+        match str::from_utf8(out) {
             Ok(s) if !s.trim().is_empty() => {
                 desc.push_str("\n--- stdout\n");
                 desc.push_str(s);
             }
             Ok(..) | Err(..) => {}
         }
-        match str::from_utf8(&out.stderr) {
+    }
+    if let Some(out) = stderr {
+        match str::from_utf8(out) {
             Ok(s) if !s.trim().is_empty() => {
                 desc.push_str("\n--- stderr\n");
                 desc.push_str(s);
@@ -381,11 +411,16 @@ pub fn process_error(
         }
     }
 
-    return ProcessError {
+    ProcessError {
         desc,
-        exit: status,
-        output: output.cloned(),
-    };
+        code,
+        stdout: stdout.map(|s| s.to_vec()),
+        stderr: stderr.map(|s| s.to_vec()),
+    }
+}
+
+pub fn exit_status_to_string(status: ExitStatus) -> String {
+    return status_to_string(status);
 
     #[cfg(unix)]
     fn status_to_string(status: ExitStatus) -> String {
diff --git a/src/cargo/util/mod.rs b/src/cargo/util/mod.rs
index b9ca5797fa2..f0408d2a920 100644
--- a/src/cargo/util/mod.rs
+++ b/src/cargo/util/mod.rs
@@ -4,7 +4,7 @@ pub use self::canonical_url::CanonicalUrl;
 pub use self::config::{homedir, Config, ConfigValue};
 pub use self::dependency_queue::DependencyQueue;
 pub use self::diagnostic_server::RustfixDiagnosticServer;
-pub use self::errors::{internal, process_error};
+pub use self::errors::{exit_status_to_string, internal, process_error, process_error_raw};
 pub use self::errors::{CargoResult, CargoResultExt, CliResult, Test};
 pub use self::errors::{CargoTestError, CliError, ProcessError};
 pub use self::flock::{FileLock, Filesystem};
diff --git a/src/cargo/util/rustc.rs b/src/cargo/util/rustc.rs
index aa713818563..a0fc2df6c94 100644
--- a/src/cargo/util/rustc.rs
+++ b/src/cargo/util/rustc.rs
@@ -1,4 +1,4 @@
-use std::collections::hash_map::{Entry, HashMap};
+use std::collections::hash_map::HashMap;
 use std::env;
 use std::hash::{Hash, Hasher};
 use std::path::{Path, PathBuf};
@@ -123,10 +123,19 @@ struct Cache {
 #[derive(Serialize, Deserialize, Debug, Default)]
 struct CacheData {
     rustc_fingerprint: u64,
-    outputs: HashMap<u64, (String, String)>,
+    outputs: HashMap<u64, Output>,
     successes: HashMap<u64, bool>,
 }
 
+#[derive(Serialize, Deserialize, Debug)]
+struct Output {
+    success: bool,
+    status: String,
+    code: Option<i32>,
+    stdout: String,
+    stderr: String,
+}
+
 impl Cache {
     fn load(rustc: &Path, rustup_rustc: &Path, cache_location: Option<PathBuf>) -> Cache {
         match (cache_location, rustc_fingerprint(rustc, rustup_rustc)) {
@@ -180,26 +189,49 @@ impl Cache {
 
     fn cached_output(&mut self, cmd: &ProcessBuilder) -> CargoResult<(String, String)> {
         let key = process_fingerprint(cmd);
-        match self.data.outputs.entry(key) {
-            Entry::Occupied(entry) => {
-                debug!("rustc info cache hit");
-                Ok(entry.get().clone())
-            }
-            Entry::Vacant(entry) => {
-                debug!("rustc info cache miss");
-                debug!("running {}", cmd);
-                let output = cmd.exec_with_output()?;
-                let stdout = String::from_utf8(output.stdout)
-                    .map_err(|e| anyhow::anyhow!("{}: {:?}", e, e.as_bytes()))
-                    .chain_err(|| anyhow::anyhow!("`{}` didn't return utf8 output", cmd))?;
-                let stderr = String::from_utf8(output.stderr)
-                    .map_err(|e| anyhow::anyhow!("{}: {:?}", e, e.as_bytes()))
-                    .chain_err(|| anyhow::anyhow!("`{}` didn't return utf8 output", cmd))?;
-                let output = (stdout, stderr);
-                entry.insert(output.clone());
-                self.dirty = true;
-                Ok(output)
-            }
+        if self.data.outputs.contains_key(&key) {
+            debug!("rustc info cache hit");
+        } else {
+            debug!("rustc info cache miss");
+            debug!("running {}", cmd);
+            let output = cmd
+                .build_command()
+                .output()
+                .chain_err(|| format!("could not execute process {} (never executed)", cmd))?;
+            let stdout = String::from_utf8(output.stdout)
+                .map_err(|e| anyhow::anyhow!("{}: {:?}", e, e.as_bytes()))
+                .chain_err(|| anyhow::anyhow!("`{}` didn't return utf8 output", cmd))?;
+            let stderr = String::from_utf8(output.stderr)
+                .map_err(|e| anyhow::anyhow!("{}: {:?}", e, e.as_bytes()))
+                .chain_err(|| anyhow::anyhow!("`{}` didn't return utf8 output", cmd))?;
+            self.data.outputs.insert(
+                key,
+                Output {
+                    success: output.status.success(),
+                    status: if output.status.success() {
+                        String::new()
+                    } else {
+                        util::exit_status_to_string(output.status)
+                    },
+                    code: output.status.code(),
+                    stdout,
+                    stderr,
+                },
+            );
+            self.dirty = true;
+        }
+        let output = &self.data.outputs[&key];
+        if output.success {
+            Ok((output.stdout.clone(), output.stderr.clone()))
+        } else {
+            Err(util::process_error_raw(
+                &format!("process didn't exit successfully: {}", cmd),
+                output.code,
+                &output.status,
+                Some(output.stdout.as_ref()),
+                Some(output.stderr.as_ref()),
+            )
+            .into())
         }
     }
 }
diff --git a/tests/testsuite/rustc_info_cache.rs b/tests/testsuite/rustc_info_cache.rs
index 26a06072199..24e3e075c66 100644
--- a/tests/testsuite/rustc_info_cache.rs
+++ b/tests/testsuite/rustc_info_cache.rs
@@ -6,11 +6,6 @@ use std::env;
 
 #[cargo_test]
 fn rustc_info_cache() {
-    // Currently detects a flag only supported on nightly. All other channels
-    // always have a miss.
-    if !cargo_test_support::is_nightly() {
-        return;
-    }
     let p = project()
         .file("src/main.rs", r#"fn main() { println!("hello"); }"#)
         .build();