diff --git a/.ci_support/linux_64_.yaml b/.ci_support/linux_64_.yaml
index 3ba5d264..2c11cee0 100644
--- a/.ci_support/linux_64_.yaml
+++ b/.ci_support/linux_64_.yaml
@@ -9,7 +9,7 @@ c_stdlib_version:
 cdt_name:
 - cos7
 channel_sources:
-- conda-forge/label/llvm_rc,conda-forge
+- conda-forge,conda-forge/label/llvm_rc
 channel_targets:
 - conda-forge llvm_rc
 cxx_compiler:
diff --git a/.ci_support/osx_64_.yaml b/.ci_support/osx_64_.yaml
index 722630ef..23432787 100644
--- a/.ci_support/osx_64_.yaml
+++ b/.ci_support/osx_64_.yaml
@@ -11,7 +11,7 @@ c_stdlib:
 c_stdlib_version:
 - '10.13'
 channel_sources:
-- conda-forge/label/llvm_rc,conda-forge
+- conda-forge,conda-forge/label/llvm_rc
 channel_targets:
 - conda-forge llvm_rc
 cxx_compiler:
diff --git a/.ci_support/osx_arm64_.yaml b/.ci_support/osx_arm64_.yaml
index c331ee38..97746927 100644
--- a/.ci_support/osx_arm64_.yaml
+++ b/.ci_support/osx_arm64_.yaml
@@ -11,7 +11,7 @@ c_stdlib:
 c_stdlib_version:
 - '11.0'
 channel_sources:
-- conda-forge/label/llvm_rc,conda-forge
+- conda-forge,conda-forge/label/llvm_rc
 channel_targets:
 - conda-forge llvm_rc
 cxx_compiler:
diff --git a/recipe/conda_build_config.yaml b/recipe/conda_build_config.yaml
index 0f1de9b0..aa56716e 100644
--- a/recipe/conda_build_config.yaml
+++ b/recipe/conda_build_config.yaml
@@ -48,7 +48,7 @@ sys_abi:                    # [osx]
   # - pre-12                  # [osx]
 
 channel_sources:
-  - conda-forge/label/llvm_rc,conda-forge
+  - conda-forge,conda-forge/label/llvm_rc
 
 # publish the pre-12 ABI & hardened builds to a separate label
 channel_targets:
diff --git a/recipe/meta.yaml b/recipe/meta.yaml
index 0b2245e2..ee131171 100644
--- a/recipe/meta.yaml
+++ b/recipe/meta.yaml
@@ -1,4 +1,4 @@
-{% set version = "19.1.0.rc3" %}
+{% set version = "19.1.0.rc4" %}
 
 {% if sys_abi is undefined %}
 {% set sys_abi = "dummy" %}
@@ -11,7 +11,7 @@ package:
 
 source:
   - url: https://github.com/llvm/llvm-project/archive/refs/tags/llvmorg-{{ version.replace(".rc", "-rc") }}.tar.gz
-    sha256: 57f926edf60a92947fa9b8b0adfdf3c6f2182a4ecf1c929176218eef619d7411
+    sha256: 570ea538eae9939e1b008c4e8055227dae3ab58054c74707ad1d5a8cb51536c3
     patches:
       # See https://discourse.llvm.org/t/shipping-custom-libc-on-macos/58606
       - patches/0001-Fix-ABI-compatibility-with-system.patch    # [sys_abi == "pre-12"]
@@ -24,7 +24,7 @@ source:
       - patches/0005-patch-__libcpp_tzdb_directory-to-allow-use-on-osx.patch
 
 build:
-  number: 1
+  number: 0
   skip: true  # [win]
   skip: true  # [ppc64le or aarch64]
 
@@ -40,9 +40,6 @@ requirements:
     - {{ compiler('c') }}
     - {{ stdlib('c') }}
     - python >3               # [not osx]
-  host:
-    - clangdev {{ version }}  # [not osx]
-    - llvmdev {{ version }}   # [not osx]
 
 outputs:
   - name: libcxx-devel
@@ -54,20 +51,16 @@ outputs:
         - libcxx =*=debug*                              # [hardening == "debug"]
     files:
       - include/c++                 # [unix]
-      - lib/libc++.a                # [unix]
-      - lib/libc++experimental.*    # [unix]
       # for C++20 modules, which are installed into $PREFIX/share/libc++
       - share/libc++/*              # [unix]
       - Library/include/c++         # [win]
-      - Library/lib/c++*.lib        # [win]
-      - Library/lib/libc++*.lib     # [win]
     requirements:
       host:
         - {{ pin_subpackage("libcxx", exact=True) }}
       run:
         # re-enable this once chrono implementation is in shared library
         # - tzdata
-        - {{ pin_subpackage("libcxx", exact=True) }}
+        - {{ pin_subpackage("libcxx", max_pin=None) }}
       run_constrained:
         - __osx <12     # [osx and (sys_abi == "pre-12")]
 
@@ -116,15 +109,12 @@ outputs:
       downstreams:              # [osx]
         - python-symengine      # [osx]
         - openturns             # [osx]
-      # disabled until libcxx-testing depends on `libcxx-devel`
-      {% if False %}
         # test current libcxx against old clang builds;
         # version correspondence is 0.{{ CLANG_MAJOR }}
         # these tests are unusual in that they use -Wl,-rpath, but not -L.
         - libcxx-testing 0.18   # [osx]
         - libcxx-testing 0.17   # [osx]
         - libcxx-testing 0.16   # [osx]
-      {% endif %}
     {% endif %}
 
   - name: libcxx
@@ -144,6 +134,11 @@ outputs:
       - lib/libc++.dylib            # [osx]
       - lib/libc++.*.dylib          # [osx]
       - Library/bin/c++*.dll        # [win]
+      # static libs for cross-compilation, due to lack of host-exports
+      - lib/libc++.a                # [unix]
+      - lib/libc++experimental.*    # [unix]
+      - Library/lib/c++*.lib        # [win]
+      - Library/lib/libc++*.lib     # [win]
     requirements:
       build:
         - {{ stdlib('c') }}
@@ -157,12 +152,12 @@ outputs:
         - sysroot_{{ target_platform }} >={{ c_stdlib_version }}    # [linux]
     test:
       commands:
-        # presence of shared libraries
+        # presence of shared & static libraries
         - test -f $PREFIX/lib/libc++.so                 # [linux]
         - test -f $PREFIX/lib/libc++.dylib              # [osx]
-        # absence of static libs & headers
-        - test ! -f $PREFIX/lib/libc++.a                # [unix]
-        - test ! -f $PREFIX/lib/libc++experimental.a    # [unix]
+        - test -f $PREFIX/lib/libc++.a                  # [unix]
+        - test -f $PREFIX/lib/libc++experimental.a      # [unix]
+        # absence of headers
         - test ! -d $PREFIX/include/c++                 # [unix]
 
   - name: libcxxabi