diff --git a/.ci_support/linux_64_cuda_compiler_version12.9microarch_level1.yaml b/.ci_support/linux_64_cuda_compiler_version12.9microarch_level1.yaml
index de7cdabbb..2ff65ba93 100644
--- a/.ci_support/linux_64_cuda_compiler_version12.9microarch_level1.yaml
+++ b/.ci_support/linux_64_cuda_compiler_version12.9microarch_level1.yaml
@@ -29,7 +29,7 @@ giflib:
 github_actions_labels:
 - cirun-openstack-cpu-2xlarge
 icu:
-- '75'
+- '78'
 libabseil:
 - '20250512'
 libcurl:
diff --git a/.ci_support/linux_64_cuda_compiler_version12.9microarch_level3.yaml b/.ci_support/linux_64_cuda_compiler_version12.9microarch_level3.yaml
index f7ff716c8..fd648c692 100644
--- a/.ci_support/linux_64_cuda_compiler_version12.9microarch_level3.yaml
+++ b/.ci_support/linux_64_cuda_compiler_version12.9microarch_level3.yaml
@@ -29,7 +29,7 @@ giflib:
 github_actions_labels:
 - cirun-openstack-cpu-2xlarge
 icu:
-- '75'
+- '78'
 libabseil:
 - '20250512'
 libcurl:
diff --git a/.ci_support/linux_64_cuda_compiler_versionNonemicroarch_level1.yaml b/.ci_support/linux_64_cuda_compiler_versionNonemicroarch_level1.yaml
index cf3f3c57e..c48e4a7cf 100644
--- a/.ci_support/linux_64_cuda_compiler_versionNonemicroarch_level1.yaml
+++ b/.ci_support/linux_64_cuda_compiler_versionNonemicroarch_level1.yaml
@@ -29,7 +29,7 @@ giflib:
 github_actions_labels:
 - cirun-openstack-cpu-2xlarge
 icu:
-- '75'
+- '78'
 libabseil:
 - '20250512'
 libcurl:
diff --git a/.ci_support/linux_64_cuda_compiler_versionNonemicroarch_level3.yaml b/.ci_support/linux_64_cuda_compiler_versionNonemicroarch_level3.yaml
index 6e720a3ff..a3097ff06 100644
--- a/.ci_support/linux_64_cuda_compiler_versionNonemicroarch_level3.yaml
+++ b/.ci_support/linux_64_cuda_compiler_versionNonemicroarch_level3.yaml
@@ -29,7 +29,7 @@ giflib:
 github_actions_labels:
 - cirun-openstack-cpu-2xlarge
 icu:
-- '75'
+- '78'
 libabseil:
 - '20250512'
 libcurl:
diff --git a/.ci_support/linux_aarch64_c_compiler_version11cuda_compiler_versionNonecxx_compiler_version11.yaml b/.ci_support/linux_aarch64_c_compiler_version11cuda_compiler_versionNonecxx_compiler_version11.yaml
index ab16ae612..3c9f7d5aa 100644
--- a/.ci_support/linux_aarch64_c_compiler_version11cuda_compiler_versionNonecxx_compiler_version11.yaml
+++ b/.ci_support/linux_aarch64_c_compiler_version11cuda_compiler_versionNonecxx_compiler_version11.yaml
@@ -27,7 +27,7 @@ giflib:
 github_actions_labels:
 - cirun-openstack-cpu-2xlarge
 icu:
-- '75'
+- '78'
 libabseil:
 - '20250512'
 libcurl:
diff --git a/.ci_support/migrations/icu78.yaml b/.ci_support/migrations/icu78.yaml
new file mode 100644
index 000000000..16b84dc25
--- /dev/null
+++ b/.ci_support/migrations/icu78.yaml
@@ -0,0 +1,8 @@
+__migrator:
+  build_number: 1
+  commit_message: Rebuild for icu 78
+  kind: version
+  migration_number: 1
+icu:
+- '78'
+migrator_ts: 1766302854.3781085
diff --git a/.ci_support/osx_64_.yaml b/.ci_support/osx_64_.yaml
index c256efd13..fefc64627 100644
--- a/.ci_support/osx_64_.yaml
+++ b/.ci_support/osx_64_.yaml
@@ -27,7 +27,7 @@ flatbuffers:
 giflib:
 - '5.2'
 icu:
-- '75'
+- '78'
 libabseil:
 - '20250512'
 libcurl:
diff --git a/.ci_support/osx_arm64_.yaml b/.ci_support/osx_arm64_.yaml
index 6bbb5ccff..3ea90e4d0 100644
--- a/.ci_support/osx_arm64_.yaml
+++ b/.ci_support/osx_arm64_.yaml
@@ -27,7 +27,7 @@ flatbuffers:
 giflib:
 - '5.2'
 icu:
-- '75'
+- '78'
 libabseil:
 - '20250512'
 libcurl:
diff --git a/.scripts/run_osx_build.sh b/.scripts/run_osx_build.sh
index a71f1c52c..03d5d2f4f 100755
--- a/.scripts/run_osx_build.sh
+++ b/.scripts/run_osx_build.sh
@@ -63,6 +63,25 @@ if [[ "${sha:-}" == "" ]]; then
   sha=$(git rev-parse HEAD)
 fi
 
+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/meta.yaml b/recipe/meta.yaml
index fb5be67d4..052dced4b 100644
--- a/recipe/meta.yaml
+++ b/recipe/meta.yaml
@@ -1,6 +1,6 @@
 {% set version = "2.19.1" %}
 {% set estimator_version = "2.15.0" %}
-{% set build = 2 %}
+{% set build = 3 %}
 
 {% if cuda_compiler_version != "None" %}
 {% set build = build + 200 %}