Mitigate problems with curl on Windows 11

master_changes.md

@@ -71,6 +71,7 @@ users)
 ## Lint
 
 ## Repository
+ * Mitigate curl/curl#13845 by falling back from --write-out to --fail if exit code 43 is returned by curl [#6168 @dra27 - fix #6120]
 
 ## Lock
 

src/repository/opamDownload.ml

@@ -20,19 +20,28 @@ let fail (s,l) = raise (Download_fail (s,l))
 let user_agent =
   CString (Printf.sprintf "opam/%s" (OpamVersion.(to_string current)))
 
-let curl_args = [
-  CString "--write-out", None;
-  CString "%%{http_code}\\n", None; (* 6.5 13-Mar-2000 *)
-  CString "--retry", None; CIdent "retry", None; (* 7.12.3 20-Dec-2004 *)
-  CString "--retry-delay", None; CString "2", None; (* 7.12.3 20-Dec-2004 *)
-  CString "--compressed",
-  Some (FIdent (OpamFilter.ident_of_string "compress")); (* 7.10 1-Oct-2002 *)
-  CString "--user-agent", None; user_agent, None; (* 4.5.1 12-Jun-1998 *)
-  CString "-L", None; (* 4.9 7-Oct-1998 *)
-  CString "-o", None; CIdent "out", None; (* 2.3 21-Aug-1997 *)
-  CString "--", None; (* End list of options; 5.0 1-Dec-1998 *)
-  CIdent "url", None;
-]
+let curl_args =
+  let main_args = [
+    CString "--retry", None; CIdent "retry", None; (* 7.12.3 20-Dec-2004 *)
+    CString "--retry-delay", None; CString "2", None; (* 7.12.3 20-Dec-2004 *)
+    CString "--compressed",
+    Some (FIdent (OpamFilter.ident_of_string "compress")); (* 7.10 1-Oct-2002 *)
+    CString "--user-agent", None; user_agent, None; (* 4.5.1 12-Jun-1998 *)
+    CString "-L", None; (* 4.9 7-Oct-1998 *)
+    CString "-o", None; CIdent "out", None; (* 2.3 21-Aug-1997 *)
+    CString "--", None; (* End list of options; 5.0 1-Dec-1998 *)
+    CIdent "url", None;
+  ] in
+  fun ~with_mitigation ->
+    if with_mitigation then
+      (* --fail is as old as curl; though the assumption that it leads to exit
+         code 22 when there's an error is probably 5.3 21-Dec-1998 (prior to
+         that it led to exit code 21) *)
+      (CString "--fail", None) :: main_args
+    else
+      (CString "--write-out", None) ::
+      (CString "%%{http_code}\\n", None) :: (* 6.5 13-Mar-2000 *)
+      main_args
 
 let wget_args = [
   CString "-t", None; CIdent "retry", None;
@@ -56,14 +65,16 @@ let ftp_args = [
   CIdent "url", None;
 ]
 
-let download_args ~url ~out ~retry ?checksum ~compress () =
+let download_args ~url ~out ~retry ?(with_curl_mitigation=false)
+                  ?checksum ~compress () =
   let cmd, _ = Lazy.force OpamRepositoryConfig.(!r.download_tool) in
   let cmd =
     match cmd with
     | [(CIdent "wget"), _] -> cmd @ wget_args
     | [(CIdent "fetch"), _] -> cmd @ fetch_args
     | [(CIdent "ftp"), _] -> cmd @ ftp_args
-    | [_] -> cmd @ curl_args (* Assume curl if the command is a single arg *)
+      (* Assume curl if the command is a single arg *)
+    | [_] -> cmd @ curl_args ~with_mitigation:with_curl_mitigation
     | _ -> cmd
   in
   OpamFilter.single_command (fun v ->
@@ -89,39 +100,14 @@ let download_args ~url ~out ~retry ?checksum ~compress () =
       | _ -> None)
     cmd
 
-let tool_return url ret =
-  match Lazy.force OpamRepositoryConfig.(!r.download_tool) with
-  | _, `Default ->
-    if OpamProcess.is_failure ret then
-      fail (Some "Download command failed",
-                Printf.sprintf "Download command failed: %s"
-                  (OpamProcess.result_summary ret))
-    else Done ()
-  | _, `Curl ->
-    if OpamProcess.is_failure ret then
-      fail (Some "Curl failed", Printf.sprintf "Curl failed: %s"
-                  (OpamProcess.result_summary ret));
-    match ret.OpamProcess.r_stdout with
-    | [] ->
-      fail (Some "curl empty response",
-                Printf.sprintf "curl: empty response while downloading %s"
-                  (OpamUrl.to_string url))
-    | l  ->
-      let code = List.hd (List.rev l) in
-      let num = try int_of_string code with Failure _ -> 999 in
-      if num >= 400 then
-        fail (Some ("curl error code " ^ code),
-                  Printf.sprintf "curl: code %s while downloading %s"
-                    code (OpamUrl.to_string url))
-      else Done ()
-
-let download_command ~compress ?checksum ~url ~dst () =
+let download_command_t ~with_curl_mitigation ~compress ?checksum ~url ~dst c =
   let cmd, args =
     match
       download_args
         ~url
         ~out:dst
         ~retry:OpamRepositoryConfig.(!r.retries)
+        ~with_curl_mitigation
         ?checksum
         ~compress
         ()
@@ -133,7 +119,59 @@ let download_command ~compress ?checksum ~url ~dst () =
   in
   let stdout = OpamSystem.temp_file ~auto_clean:false "dl" in
   OpamProcess.Job.finally (fun () -> OpamSystem.remove_file stdout) @@ fun () ->
-  OpamSystem.make_command ~allow_stdin:false ~stdout cmd args @@> tool_return url
+  OpamSystem.make_command ~allow_stdin:false ~stdout cmd args @@> c
+
+let tool_return redownload_command url ret =
+  match Lazy.force OpamRepositoryConfig.(!r.download_tool) with
+  | _, `Default ->
+    if OpamProcess.is_failure ret then
+      fail (Some "Download command failed",
+                Printf.sprintf "Download command failed: %s"
+                  (OpamProcess.result_summary ret))
+    else Done ()
+  | _, `Curl ->
+    if OpamProcess.is_failure ret then
+      if ret.r_code = 43 then begin
+        (* Code 43 is CURLE_BAD_FUNCTION_ARGUMENT (7.1 7-Aug-2000). This should
+           never be encountered using the curl binary, so we assume that it's
+           a manifestation of curl/curl#13845 (see also #6120). *)
+        log "Attempting to mitigate curl/curl#13845";
+        redownload_command ~with_curl_mitigation:true @@ function ret ->
+          if OpamProcess.is_failure ret then
+            if ret.r_code = 22 then
+              (* If this broken version of curl persists for some time, it is
+                 relatively straightforward to parse the http response code from
+                 the message, as it hasn't changed. *)
+              fail (Some "curl failed owing to a server-side issue",
+                    Printf.sprintf "curl failed with server-side error: %s"
+                      (OpamProcess.result_summary ret))
+            else
+              fail (Some "curl failed",
+                    Printf.sprintf "curl failed: %s"
+                      (OpamProcess.result_summary ret))
+          else Done ()
+      end else
+        fail (Some "curl failed", Printf.sprintf "curl failed: %s"
+                (OpamProcess.result_summary ret))
+    else
+      match ret.OpamProcess.r_stdout with
+      | [] ->
+        fail (Some "curl empty response",
+              Printf.sprintf "curl: empty response while downloading %s"
+                (OpamUrl.to_string url))
+      | l  ->
+        let code = List.hd (List.rev l) in
+        let num = try int_of_string code with Failure _ -> 999 in
+        if num >= 400 then
+          fail (Some ("curl error code " ^ code),
+                Printf.sprintf "curl: code %s while downloading %s"
+                  code (OpamUrl.to_string url))
+        else Done ()
+
+let download_command ~compress ?checksum ~url ~dst () =
+  let download_command = download_command_t ~compress ?checksum ~url ~dst in
+  download_command ~with_curl_mitigation:false
+  @@ tool_return download_command url
 
 let really_download
     ?(quiet=false) ~overwrite ?(compress=false) ?checksum ?(validate=true)

tests/reftests/download.test

@@ -64,9 +64,9 @@ The following actions will be performed:
 <><> Processing actions <><><><><><><><><><><><><><><><><><><><><><><><><><><><>
 Processing  1/1: [foo.1: http]
 + curl "--another-args" "3"
-[ERROR] Failed to get sources of foo.1: Curl failed
+[ERROR] Failed to get sources of foo.1: curl failed
 
-OpamSolution.Fetch_fail("https://github.com/UnixJunkie/get_line/archive/v1.0.0.tar.gz (Curl failed: \"curl --another-args 3\" exited with code 2)")
+OpamSolution.Fetch_fail("https://github.com/UnixJunkie/get_line/archive/v1.0.0.tar.gz (curl failed: \"curl --another-args 3\" exited with code 2)")
 
 
 <><> Error report <><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>