fetchurl: use __structuredAttrs = true and pass curlOptsList directly

pkgs/build-support/fetchurl/builder.sh

@@ -1,3 +1,4 @@
+source "$NIX_ATTRS_SH_FILE"
 source $mirrorsFile
 
 curlVersion=$(curl -V | head -1 | cut -d' ' -f2)
@@ -22,10 +23,10 @@ if ! [ -f "$SSL_CERT_FILE" ]; then
     curl+=(--insecure)
 fi
 
-eval "curl+=($curlOptsList)"
+curl+=("${curlOptsList[@]}")
 
 curl+=(
-    $curlOpts
+    ${curlOpts[*]}
     $NIX_CURL_FLAGS
 )
 

pkgs/build-support/fetchurl/default.nix

@@ -136,6 +136,7 @@ lib.extendMkDerivation {
 
       # Passthru information, if any.
       passthru ? { },
+
       # Doing the download on a remote machine just duplicates network
       # traffic, so don't do that by default
       preferLocalBuild ? true,
@@ -238,6 +239,8 @@ lib.extendMkDerivation {
 
     derivationArgs
     // {
+      __structuredAttrs = true;
+
       name =
         if finalAttrs.pname or null != null && finalAttrs.version or null != null then
           "${finalAttrs.pname}-${finalAttrs.version}"
@@ -297,9 +300,8 @@ lib.extendMkDerivation {
         ''
       ) curlOpts;
 
-      curlOptsList = lib.escapeShellArgs curlOptsList;
-
       inherit
+        curlOptsList
         downloadToTemp
         executable
         mirrorsFile