Generate the nix.conf docs from the source code

This means we don't have two (divergent) sets of option descriptions
anymore.

1 files changed, 22 insertions, 7 deletions

diff --git a/src/libstore/filetransfer.hh b/src/libstore/filetransfer.hh
index 25ade0add..0d608c8d8 100644
--- a/src/libstore/filetransfer.hh
+++ b/src/libstore/filetransfer.hh
@@ -17,15 +17,30 @@ struct FileTransferSettings : Config
     Setting<std::string> userAgentSuffix{this, "", "user-agent-suffix",
         "String appended to the user agent in HTTP requests."};
 
-    Setting<size_t> httpConnections{this, 25, "http-connections",
-        "Number of parallel HTTP connections.",
+    Setting<size_t> httpConnections{
+        this, 25, "http-connections",
+        R"(
+          The maximum number of parallel TCP connections used to fetch
+          files from binary caches and by other downloads. It defaults
+          to 25. 0 means no limit.
+        )",
         {"binary-caches-parallel-connections"}};
 
-    Setting<unsigned long> connectTimeout{this, 0, "connect-timeout",
-        "Timeout for connecting to servers during downloads. 0 means use curl's builtin default."};
-
-    Setting<unsigned long> stalledDownloadTimeout{this, 300, "stalled-download-timeout",
-        "Timeout (in seconds) for receiving data from servers during download. Nix cancels idle downloads after this timeout's duration."};
+    Setting<unsigned long> connectTimeout{
+        this, 0, "connect-timeout",
+        R"(
+          The timeout (in seconds) for establishing connections in the
+          binary cache substituter. It corresponds to `curl`’s
+          `--connect-timeout` option.
+        )"};
+
+    Setting<unsigned long> stalledDownloadTimeout{
+        this, 300, "stalled-download-timeout",
+        R"(
+          The timeout (in seconds) for receiving data from servers
+          during download. Nix cancels idle downloads after this
+          timeout's duration.
+        )"};
 
     Setting<unsigned int> tries{this, 5, "download-attempts",
         "How often Nix will attempt to download a file before giving up."};