From 5f53a024a37f6f6a664afdca95cd77508f28f2c6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C2=B7=F0=90=91=91=F0=90=91=B4=F0=90=91=95=F0=90=91=91?=
 =?UTF-8?q?=F0=90=91=A9=F0=90=91=A4?= <toastal@posteo.net>
Date: Tue, 2 Dec 2025 23:21:59 +0700
Subject: [PATCH 1/2] fetchdarcs: remove remnant `--partial`

---
 pkgs/build-support/fetchdarcs/builder.sh | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/pkgs/build-support/fetchdarcs/builder.sh b/pkgs/build-support/fetchdarcs/builder.sh
index e1c5d7745d35..8137209686b6 100644
--- a/pkgs/build-support/fetchdarcs/builder.sh
+++ b/pkgs/build-support/fetchdarcs/builder.sh
@@ -1,3 +1,5 @@
+set -u
+
 tagtext=""
 tagflags=""
 # Darcs hashes are sha1 (120 bits, 40-character hex)
@@ -12,7 +14,7 @@ elif test -n "$context"; then
     tagflags="--context=$context"
 fi
 
-echo "Cloning $url $partial ${tagtext} into $out"
+echo "Cloning $url ${tagtext} into $out"
 
 darcs clone --lazy $tagflags "$url" "$out"
 # remove metadata, because it can change

From 2a1e98f0b2bf94d3100148d6c9744926c8235a43 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C2=B7=F0=90=91=91=F0=90=91=B4=F0=90=91=95=F0=90=91=91?=
 =?UTF-8?q?=F0=90=91=A9=F0=90=91=A4?= <toastal@posteo.net>
Date: Tue, 2 Dec 2025 23:24:39 +0700
Subject: [PATCH 2/2] fetchdarcs: add mirror support

---
 pkgs/build-support/fetchdarcs/builder.sh  | 19 +++++++++++++++----
 pkgs/build-support/fetchdarcs/default.nix |  7 ++++++-
 2 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/pkgs/build-support/fetchdarcs/builder.sh b/pkgs/build-support/fetchdarcs/builder.sh
index 8137209686b6..adc9c55939c3 100644
--- a/pkgs/build-support/fetchdarcs/builder.sh
+++ b/pkgs/build-support/fetchdarcs/builder.sh
@@ -14,8 +14,19 @@ elif test -n "$context"; then
     tagflags="--context=$context"
 fi
 
-echo "Cloning $url ${tagtext} into $out"
+# Repository list may contain ?. No glob expansion for that.
+set -o noglob
 
-darcs clone --lazy $tagflags "$url" "$out"
-# remove metadata, because it can change
-rm -rf "$out/_darcs"
+for repository in $repositories; do
+    echo "Trying to clone $repository $tagtext into $out …"
+    if darcs clone --lazy $tagflags "$repository" "$out"; then
+        # remove metadata, because it can change
+        rm -rf "$out/_darcs"
+        exit 0
+    fi
+done
+
+set +o noglob
+
+echo "Error: couldn’t clone repository from any mirror" 1>&2
+exit 1
diff --git a/pkgs/build-support/fetchdarcs/default.nix b/pkgs/build-support/fetchdarcs/default.nix
index 2d24ddaecbd4..d6a9093c76dc 100644
--- a/pkgs/build-support/fetchdarcs/default.nix
+++ b/pkgs/build-support/fetchdarcs/default.nix
@@ -8,7 +8,11 @@
 lib.makeOverridable (
   lib.fetchers.withNormalizedHash { } (
     {
+      # Repository to fetch
       url,
+      # Additional list of repositories specifying alternative download
+      # location to be tried in order, if the prior repository failed to fetch.
+      mirrors ? [ ],
       rev ? null,
       context ? null,
       outputHash ? lib.fakeHash,
@@ -27,11 +31,12 @@ lib.makeOverridable (
       outputHashMode = "recursive";
 
       inherit
-        url
         rev
         context
         name
         ;
+
+      repositories = [ url ] ++ mirrors;
     }
   )
 )