diff --git a/.ci_support/linux_64_blas_implgenericchannel_targetsconda-forge_maincuda_compiler_version12.9is_rcFalse.yaml b/.ci_support/linux_64_blas_implgenericchannel_targetsconda-forge_maincuda_compiler_version12.9is_rcFalse.yaml
index 128dd0f14..2569f0525 100644
--- a/.ci_support/linux_64_blas_implgenericchannel_targetsconda-forge_maincuda_compiler_version12.9is_rcFalse.yaml
+++ b/.ci_support/linux_64_blas_implgenericchannel_targetsconda-forge_maincuda_compiler_version12.9is_rcFalse.yaml
@@ -25,7 +25,7 @@ cxx_compiler_version:
 docker_image:
 - quay.io/condaforge/linux-anvil-x86_64:alma9
 fmt:
-- '12.0'
+- '12.1'
 github_actions_labels:
 - cirun-openstack-gpu-2xlarge
 is_rc:
diff --git a/.ci_support/linux_64_blas_implgenericchannel_targetsconda-forge_maincuda_compiler_versionNoneis_rcFalse.yaml b/.ci_support/linux_64_blas_implgenericchannel_targetsconda-forge_maincuda_compiler_versionNoneis_rcFalse.yaml
index 96be2927b..72f926c61 100644
--- a/.ci_support/linux_64_blas_implgenericchannel_targetsconda-forge_maincuda_compiler_versionNoneis_rcFalse.yaml
+++ b/.ci_support/linux_64_blas_implgenericchannel_targetsconda-forge_maincuda_compiler_versionNoneis_rcFalse.yaml
@@ -25,7 +25,7 @@ cxx_compiler_version:
 docker_image:
 - quay.io/condaforge/linux-anvil-x86_64:alma9
 fmt:
-- '12.0'
+- '12.1'
 github_actions_labels:
 - cirun-openstack-gpu-2xlarge
 is_rc:
diff --git a/.ci_support/linux_64_blas_implmklchannel_targetsconda-forge_maincuda_compiler_version12.9is_rcFalse.yaml b/.ci_support/linux_64_blas_implmklchannel_targetsconda-forge_maincuda_compiler_version12.9is_rcFalse.yaml
index 1134e6b03..e26700b68 100644
--- a/.ci_support/linux_64_blas_implmklchannel_targetsconda-forge_maincuda_compiler_version12.9is_rcFalse.yaml
+++ b/.ci_support/linux_64_blas_implmklchannel_targetsconda-forge_maincuda_compiler_version12.9is_rcFalse.yaml
@@ -25,7 +25,7 @@ cxx_compiler_version:
 docker_image:
 - quay.io/condaforge/linux-anvil-x86_64:alma9
 fmt:
-- '12.0'
+- '12.1'
 github_actions_labels:
 - cirun-openstack-gpu-2xlarge
 is_rc:
diff --git a/.ci_support/linux_64_blas_implmklchannel_targetsconda-forge_maincuda_compiler_versionNoneis_rcFalse.yaml b/.ci_support/linux_64_blas_implmklchannel_targetsconda-forge_maincuda_compiler_versionNoneis_rcFalse.yaml
index 7ea16ec20..ba0126a43 100644
--- a/.ci_support/linux_64_blas_implmklchannel_targetsconda-forge_maincuda_compiler_versionNoneis_rcFalse.yaml
+++ b/.ci_support/linux_64_blas_implmklchannel_targetsconda-forge_maincuda_compiler_versionNoneis_rcFalse.yaml
@@ -25,7 +25,7 @@ cxx_compiler_version:
 docker_image:
 - quay.io/condaforge/linux-anvil-x86_64:alma9
 fmt:
-- '12.0'
+- '12.1'
 github_actions_labels:
 - cirun-openstack-gpu-2xlarge
 is_rc:
diff --git a/.ci_support/linux_aarch64_channel_targetsconda-forge_maincuda_compiler_version12.9is_rcFalse.yaml b/.ci_support/linux_aarch64_channel_targetsconda-forge_maincuda_compiler_version12.9is_rcFalse.yaml
index 693408283..f25102f27 100644
--- a/.ci_support/linux_aarch64_channel_targetsconda-forge_maincuda_compiler_version12.9is_rcFalse.yaml
+++ b/.ci_support/linux_aarch64_channel_targetsconda-forge_maincuda_compiler_version12.9is_rcFalse.yaml
@@ -25,7 +25,7 @@ cxx_compiler_version:
 docker_image:
 - quay.io/condaforge/linux-anvil-x86_64:alma9
 fmt:
-- '12.0'
+- '12.1'
 github_actions_labels:
 - cirun-openstack-gpu-2xlarge
 is_rc:
diff --git a/.ci_support/linux_aarch64_channel_targetsconda-forge_maincuda_compiler_versionNoneis_rcFalse.yaml b/.ci_support/linux_aarch64_channel_targetsconda-forge_maincuda_compiler_versionNoneis_rcFalse.yaml
index 1721a78b1..2cd6684f4 100644
--- a/.ci_support/linux_aarch64_channel_targetsconda-forge_maincuda_compiler_versionNoneis_rcFalse.yaml
+++ b/.ci_support/linux_aarch64_channel_targetsconda-forge_maincuda_compiler_versionNoneis_rcFalse.yaml
@@ -25,7 +25,7 @@ cxx_compiler_version:
 docker_image:
 - quay.io/condaforge/linux-anvil-x86_64:alma9
 fmt:
-- '12.0'
+- '12.1'
 github_actions_labels:
 - cirun-openstack-gpu-2xlarge
 is_rc:
diff --git a/.ci_support/migrations/fmt121_spdlog117.yaml b/.ci_support/migrations/fmt121_spdlog117.yaml
new file mode 100644
index 000000000..f46fced4a
--- /dev/null
+++ b/.ci_support/migrations/fmt121_spdlog117.yaml
@@ -0,0 +1,10 @@
+__migrator:
+  build_number: 1
+  commit_message: Rebuild for fmt 12.1 and spdlog 1.17
+  kind: version
+  migration_number: 1
+migrator_ts: 1767674179.1402016
+fmt:
+- '12.1'
+spdlog:
+- '1.17'
diff --git a/.ci_support/migrations/fmt12_spdlog116.yaml b/.ci_support/migrations/fmt12_spdlog116.yaml
deleted file mode 100644
index 87c31a2ba..000000000
--- a/.ci_support/migrations/fmt12_spdlog116.yaml
+++ /dev/null
@@ -1,10 +0,0 @@
-__migrator:
-  build_number: 1
-  commit_message: Rebuild for fmt 12.0 and spdlog 1.16
-  kind: version
-  migration_number: 1
-migrator_ts: 1760196591.995821
-fmt:
-- '12.0'
-spdlog:
-- '1.16'
diff --git a/.ci_support/osx_64_blas_implgenericchannel_targetsconda-forge_mainis_rcFalse.yaml b/.ci_support/osx_64_blas_implgenericchannel_targetsconda-forge_mainis_rcFalse.yaml
index 2ff370171..c59908bd1 100644
--- a/.ci_support/osx_64_blas_implgenericchannel_targetsconda-forge_mainis_rcFalse.yaml
+++ b/.ci_support/osx_64_blas_implgenericchannel_targetsconda-forge_mainis_rcFalse.yaml
@@ -25,7 +25,7 @@ cxx_compiler:
 cxx_compiler_version:
 - '19'
 fmt:
-- '12.0'
+- '12.1'
 github_actions_labels:
 - cirun-macos-m4-large
 is_rc:
diff --git a/.ci_support/osx_64_blas_implmklchannel_targetsconda-forge_mainis_rcFalse.yaml b/.ci_support/osx_64_blas_implmklchannel_targetsconda-forge_mainis_rcFalse.yaml
index e08cae1bb..cc6f71fea 100644
--- a/.ci_support/osx_64_blas_implmklchannel_targetsconda-forge_mainis_rcFalse.yaml
+++ b/.ci_support/osx_64_blas_implmklchannel_targetsconda-forge_mainis_rcFalse.yaml
@@ -25,7 +25,7 @@ cxx_compiler:
 cxx_compiler_version:
 - '19'
 fmt:
-- '12.0'
+- '12.1'
 github_actions_labels:
 - cirun-macos-m4-large
 is_rc:
diff --git a/.ci_support/osx_arm64_channel_targetsconda-forge_mainis_rcFalse.yaml b/.ci_support/osx_arm64_channel_targetsconda-forge_mainis_rcFalse.yaml
index 9815c8bd2..14813d153 100644
--- a/.ci_support/osx_arm64_channel_targetsconda-forge_mainis_rcFalse.yaml
+++ b/.ci_support/osx_arm64_channel_targetsconda-forge_mainis_rcFalse.yaml
@@ -25,7 +25,7 @@ cxx_compiler:
 cxx_compiler_version:
 - '19'
 fmt:
-- '12.0'
+- '12.1'
 github_actions_labels:
 - cirun-macos-m4-large
 is_rc:
diff --git a/.ci_support/win_64_channel_targetsconda-forge_maincuda_compiler_version12.8is_rcFalse.yaml b/.ci_support/win_64_channel_targetsconda-forge_maincuda_compiler_version12.8is_rcFalse.yaml
index 61349d925..9d3fe548e 100644
--- a/.ci_support/win_64_channel_targetsconda-forge_maincuda_compiler_version12.8is_rcFalse.yaml
+++ b/.ci_support/win_64_channel_targetsconda-forge_maincuda_compiler_version12.8is_rcFalse.yaml
@@ -17,7 +17,7 @@ cudnn:
 cxx_compiler:
 - vs2022
 fmt:
-- '12.0'
+- '12.1'
 github_actions_labels:
 - cirun-azure-windows-4xlarge
 is_rc:
diff --git a/.ci_support/win_64_channel_targetsconda-forge_maincuda_compiler_versionNoneis_rcFalse.yaml b/.ci_support/win_64_channel_targetsconda-forge_maincuda_compiler_versionNoneis_rcFalse.yaml
index 8f4871b4d..f0dc0d666 100644
--- a/.ci_support/win_64_channel_targetsconda-forge_maincuda_compiler_versionNoneis_rcFalse.yaml
+++ b/.ci_support/win_64_channel_targetsconda-forge_maincuda_compiler_versionNoneis_rcFalse.yaml
@@ -17,7 +17,7 @@ cudnn:
 cxx_compiler:
 - vs2022
 fmt:
-- '12.0'
+- '12.1'
 github_actions_labels:
 - cirun-azure-windows-4xlarge
 is_rc:
diff --git a/.scripts/run_osx_build.sh b/.scripts/run_osx_build.sh
index 4bba44792..bac7141a9 100755
--- a/.scripts/run_osx_build.sh
+++ b/.scripts/run_osx_build.sh
@@ -63,8 +63,24 @@ if [[ "${sha:-}" == "" ]]; then
   sha=$(git rev-parse HEAD)
 fi
 
-# HACK
-cp .scripts/download_osx_sdk.sh $CONDA_PREFIX/bin/
+if [[ "${OSX_SDK_DIR:-}" == "" ]]; then
+  if [[ "${CI:-}" == "" ]]; then
+    echo "Please set OSX_SDK_DIR to a directory where SDKs can be downloaded to. Aborting"
+    exit 1
+  else
+    export OSX_SDK_DIR=/opt/conda-sdks
+    /usr/bin/sudo mkdir -p "${OSX_SDK_DIR}"
+    /usr/bin/sudo chown "${USER}" "${OSX_SDK_DIR}"
+  fi
+else
+  if tmpf=$(mktemp -p "$OSX_SDK_DIR" tmp.XXXXXXXX 2>/dev/null); then
+      rm -f "$tmpf"
+      echo "OSX_SDK_DIR is writeable without sudo, continuing"
+  else
+      echo "User-provided OSX_SDK_DIR is not writeable for current user! Aborting"
+      exit 1
+  fi
+fi
 
 echo -e "\n\nRunning the build setup script."
 source run_conda_forge_build_setup
diff --git a/recipe/build.sh b/recipe/build.sh
index dd24fc2d9..870380065 100644
--- a/recipe/build.sh
+++ b/recipe/build.sh
@@ -302,7 +302,11 @@ case ${PKG_NAME} in
     for f in bin/* lib/* share/* include/*; do
       if [[ -e "$PREFIX/$f" ]]; then
         rm -rf $f
-        ln -sf $PREFIX/$f $PWD/$f
+        # do not symlink include files back
+        # https://github.com/conda-forge/pytorch-cpu-feedstock/issues/447#issuecomment-3712968499
+        if [[ ${f} != include/* ]]; then
+          ln -sf $PREFIX/$f $PWD/$f
+        fi
       fi
     done
     popd
diff --git a/recipe/meta.yaml b/recipe/meta.yaml
index 5e6672850..9826fedb4 100644
--- a/recipe/meta.yaml
+++ b/recipe/meta.yaml
@@ -1,6 +1,6 @@
 # if you wish to build release candidate number X, append the version string with ".rcX"
 {% set version = "2.9.1" %}
-{% set build = 1 %}
+{% set build = 2 %}
 
 # Use a higher build number for the CUDA variant, to ensure that it's
 # preferred by conda's solver, and it's preferentially