Don't display headers in spurious warning message.

The headers can significantly contribute to noise in the output,
drowning out the rest of the output. Most investigation will likely be
focused on the case where cargo completely fails to download, so this
only shows the full detail in the final error message.

Author: ehuss

src/cargo/util/errors.rs

@@ -2,7 +2,7 @@
 
 use anyhow::Error;
 use curl::easy::Easy;
-use std::fmt;
+use std::fmt::{self, Write};
 use std::path::PathBuf;
 
 use super::truncate_with_ellipsis;
@@ -50,27 +50,41 @@ impl HttpNotSuccessful {
             headers,
         }
     }
-}
 
-impl fmt::Display for HttpNotSuccessful {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+    /// Renders the error in a compact form.
+    pub fn display_short(&self) -> String {
+        self.render(false)
+    }
+
+    fn render(&self, show_headers: bool) -> String {
+        let mut result = String::new();
         let body = std::str::from_utf8(&self.body)
             .map(|s| truncate_with_ellipsis(s, 512))
             .unwrap_or_else(|_| format!("[{} non-utf8 bytes]", self.body.len()));
 
         write!(
-            f,
+            result,
             "failed to get successful HTTP response from `{}`",
             self.url
-        )?;
+        )
+        .unwrap();
         if let Some(ip) = &self.ip {
-            write!(f, " ({ip})")?;
+            write!(result, " ({ip})").unwrap();
         }
-        write!(f, ", got {}\n", self.code,)?;
-        if !self.headers.is_empty() {
-            write!(f, "debug headers:\n{}\n", self.headers.join("\n"))?;
+        write!(result, ", got {}\n", self.code).unwrap();
+        if show_headers {
+            if !self.headers.is_empty() {
+                write!(result, "debug headers:\n{}\n", self.headers.join("\n")).unwrap();
+            }
         }
-        write!(f, "body:\n{body}",)
+        write!(result, "body:\n{body}").unwrap();
+        result
+    }
+}
+
+impl fmt::Display for HttpNotSuccessful {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.write_str(&self.render(true))
     }
 }
 

src/cargo/util/network/retry.rs

@@ -44,10 +44,13 @@ impl<'a> Retry<'a> {
     pub fn r#try<T>(&mut self, f: impl FnOnce() -> CargoResult<T>) -> RetryResult<T> {
         match f() {
             Err(ref e) if maybe_spurious(e) && self.retries < self.max_retries => {
+                let err_msg = e
+                    .downcast_ref::<HttpNotSuccessful>()
+                    .map(|http_err| http_err.display_short())
+                    .unwrap_or_else(|| e.root_cause().to_string());
                 let msg = format!(
-                    "spurious network error ({} tries remaining): {}",
+                    "spurious network error ({} tries remaining): {err_msg}",
                     self.max_retries - self.retries,
-                    e.root_cause(),
                 );
                 if let Err(e) = self.config.shell().warn(msg) {
                     return RetryResult::Err(e);

tests/testsuite/registry.rs

@@ -3319,26 +3319,14 @@ fn debug_header_message_index() {
 [UPDATING] `dummy-registry` index
 warning: spurious network error (3 tries remaining): \
     failed to get successful HTTP response from `http://127.0.0.1:[..]/index/3/b/bar` (127.0.0.1), got 503
-debug headers:
-x-amz-cf-pop: SFO53-P2
-x-amz-cf-id: vEc3osJrCAXVaciNnF4Vev-hZFgnYwmNZtxMKRJ5bF6h9FTOtbTMnA==
-x-cache: Hit from cloudfront
 body:
 Please slow down
 warning: spurious network error (2 tries remaining): \
     failed to get successful HTTP response from `http://127.0.0.1:[..]/index/3/b/bar` (127.0.0.1), got 503
-debug headers:
-x-amz-cf-pop: SFO53-P2
-x-amz-cf-id: vEc3osJrCAXVaciNnF4Vev-hZFgnYwmNZtxMKRJ5bF6h9FTOtbTMnA==
-x-cache: Hit from cloudfront
 body:
 Please slow down
 warning: spurious network error (1 tries remaining): \
     failed to get successful HTTP response from `http://127.0.0.1:[..]/index/3/b/bar` (127.0.0.1), got 503
-debug headers:
-x-amz-cf-pop: SFO53-P2
-x-amz-cf-id: vEc3osJrCAXVaciNnF4Vev-hZFgnYwmNZtxMKRJ5bF6h9FTOtbTMnA==
-x-cache: Hit from cloudfront
 body:
 Please slow down
 error: failed to get `bar` as a dependency of package `foo v0.1.0 ([ROOT]/foo)`
@@ -3393,26 +3381,14 @@ fn debug_header_message_dl() {
 [DOWNLOADING] crates ...
 warning: spurious network error (3 tries remaining): \
     failed to get successful HTTP response from `http://127.0.0.1:[..]/dl/bar/1.0.0/download` (127.0.0.1), got 503
-debug headers:
-x-amz-cf-pop: SFO53-P2
-x-amz-cf-id: vEc3osJrCAXVaciNnF4Vev-hZFgnYwmNZtxMKRJ5bF6h9FTOtbTMnA==
-x-cache: Hit from cloudfront
 body:
 Please slow down
 warning: spurious network error (2 tries remaining): \
     failed to get successful HTTP response from `http://127.0.0.1:[..]/dl/bar/1.0.0/download` (127.0.0.1), got 503
-debug headers:
-x-amz-cf-pop: SFO53-P2
-x-amz-cf-id: vEc3osJrCAXVaciNnF4Vev-hZFgnYwmNZtxMKRJ5bF6h9FTOtbTMnA==
-x-cache: Hit from cloudfront
 body:
 Please slow down
 warning: spurious network error (1 tries remaining): \
     failed to get successful HTTP response from `http://127.0.0.1:[..]/dl/bar/1.0.0/download` (127.0.0.1), got 503
-debug headers:
-x-amz-cf-pop: SFO53-P2
-x-amz-cf-id: vEc3osJrCAXVaciNnF4Vev-hZFgnYwmNZtxMKRJ5bF6h9FTOtbTMnA==
-x-cache: Hit from cloudfront
 body:
 Please slow down
 error: failed to download from `http://127.0.0.1:[..]/dl/bar/1.0.0/download`