diff --git a/.scripts/build_steps.sh b/.scripts/build_steps.sh
index beda247..9121002 100755
--- a/.scripts/build_steps.sh
+++ b/.scripts/build_steps.sh
@@ -34,9 +34,9 @@ CONDARC
 export CONDA_LIBMAMBA_SOLVER_NO_CHANNELS_FROM_INSTALLED=1
 
 mamba install --update-specs --yes --quiet --channel conda-forge --strict-channel-priority \
-    pip mamba conda-build boa conda-forge-ci-setup=4
+    pip mamba conda-build conda-forge-ci-setup=4 "conda-build>=24.1"
 mamba update --update-specs --yes --quiet --channel conda-forge --strict-channel-priority \
-    pip mamba conda-build boa conda-forge-ci-setup=4
+    pip mamba conda-build conda-forge-ci-setup=4 "conda-build>=24.1"
 
 # set up the condarc
 setup_conda_rc "${FEEDSTOCK_ROOT}" "${RECIPE_ROOT}" "${CONFIG_FILE}"
@@ -68,7 +68,7 @@ if [[ "${BUILD_WITH_CONDA_DEBUG:-0}" == 1 ]]; then
     # Drop into an interactive shell
     /bin/bash
 else
-    conda mambabuild "${RECIPE_ROOT}" -m "${CI_SUPPORT}/${CONFIG}.yaml" \
+    conda build "${RECIPE_ROOT}" -m "${CI_SUPPORT}/${CONFIG}.yaml" \
         --suppress-variables ${EXTRA_CB_OPTIONS:-} \
         --clobber-file "${CI_SUPPORT}/clobber_${CONFIG}.yaml" \
         --extra-meta flow_run_id="${flow_run_id:-}" remote_url="${remote_url:-}" sha="${sha:-}"
diff --git a/.scripts/run_osx_build.sh b/.scripts/run_osx_build.sh
index 9259eb9..16daa69 100755
--- a/.scripts/run_osx_build.sh
+++ b/.scripts/run_osx_build.sh
@@ -26,9 +26,9 @@ export CONDA_SOLVER="libmamba"
 export CONDA_LIBMAMBA_SOLVER_NO_CHANNELS_FROM_INSTALLED=1
 
 mamba install --update-specs --quiet --yes --channel conda-forge --strict-channel-priority \
-    pip mamba conda-build boa conda-forge-ci-setup=4
+    pip mamba conda-build conda-forge-ci-setup=4 "conda-build>=24.1"
 mamba update --update-specs --yes --quiet --channel conda-forge --strict-channel-priority \
-    pip mamba conda-build boa conda-forge-ci-setup=4
+    pip mamba conda-build conda-forge-ci-setup=4 "conda-build>=24.1"
 
 
 
@@ -81,7 +81,7 @@ else
         EXTRA_CB_OPTIONS="${EXTRA_CB_OPTIONS:-} --no-test"
     fi
 
-    conda mambabuild ./recipe -m ./.ci_support/${CONFIG}.yaml \
+    conda build ./recipe -m ./.ci_support/${CONFIG}.yaml \
         --suppress-variables ${EXTRA_CB_OPTIONS:-} \
         --clobber-file ./.ci_support/clobber_${CONFIG}.yaml \
         --extra-meta flow_run_id="$flow_run_id" remote_url="$remote_url" sha="$sha"
diff --git a/build-locally.py b/build-locally.py
index 3f4b7a7..e0d408d 100755
--- a/build-locally.py
+++ b/build-locally.py
@@ -64,8 +64,9 @@ def verify_config(ns):
     elif ns.config.startswith("osx"):
         if "OSX_SDK_DIR" not in os.environ:
             raise RuntimeError(
-                "Need OSX_SDK_DIR env variable set. Run 'export OSX_SDK_DIR=SDKs' "
-                "to download the SDK automatically to 'SDKs/MacOSX<ver>.sdk'. "
+                "Need OSX_SDK_DIR env variable set. Run 'export OSX_SDK_DIR=$PWD/SDKs' "
+                "to download the SDK automatically to '$PWD/SDKs/MacOSX<ver>.sdk'. "
+                "Note: OSX_SDK_DIR must be set to an absolute path. "
                 "Setting this variable implies agreement to the licensing terms of the SDK by Apple."
             )
 
diff --git a/recipe/meta.yaml b/recipe/meta.yaml
index 7922d22..c518205 100644
--- a/recipe/meta.yaml
+++ b/recipe/meta.yaml
@@ -1,5 +1,5 @@
 {% set name = "qsimcirq" %}
-{% set version = "0.20.2" %}
+{% set version = "0.21.0" %}
 {% set build = 0 %}
 
 # Prioritize over CPU builds
@@ -16,7 +16,7 @@ package:
 
 source:
   url: https://github.com/quantumlib/qsim/archive/refs/tags/v{{ version }}.tar.gz
-  sha256: 8fe00007da8a9e09563688bb9c41895327a766c24011e8f529cffe8b82a19f09
+  sha256: 1f13137579a426e0ecc40e87d17c48d44fa84f5da6501ae5285e3206fb625ccd
   patches:
     - patches/0007-Always-skip-test_cirq_qsim_gpu_amplitudes-because-no.patch  # [cuda_compiler != "None"]
     - patches/0010-Do-not-set-includes-on-Apple-arm64-in-basis.patch