diff --git a/.drone.star b/.drone.star
index 20337e37c..8420524e3 100644
--- a/.drone.star
+++ b/.drone.star
@@ -8,7 +8,7 @@
 # As the yaml syntax for Drone CI is rather limited.
 #
 #
-globalenv={'B2_CI_VERSION': '1', 'B2_VARIANT': 'debug,release', 'B2_FLAGS': 'warnings=extra warnings-as-errors=on'}
+globalenv={'B2_CI_VERSION': '1', 'B2_VARIANT': 'debug,release', 'B2_FLAGS': 'warnings=extra warnings-as-errors=on', 'UBUNTU_TOOLCHAIN_DISABLE': 'true'}
 linuxglobalimage="cppalliance/droneubuntu1804:1"
 windowsglobalimage="cppalliance/dronevs2019"
 
@@ -44,7 +44,7 @@ def main(ctx):
   linux_cxx("gcc 14", "g++-14", packages="g++-14", buildtype="boost", buildscript="drone", image="cppalliance/droneubuntu2404:1", environment={'B2_TOOLSET': 'gcc-14', 'B2_CXXSTD': '20'}, globalenv=globalenv),
   linux_cxx("Clang 3.8", "clang++-3.8", packages="clang-3.8 g++", llvm_os='xenial', llvm_ver='3.8', buildtype="boost", buildscript="drone", image="cppalliance/droneubuntu1604:1", environment={'B2_TOOLSET': 'clang-3.8', 'B2_CXXSTD': '11', 'B2_SEPARATE_BOOTSTRAP': '1', 'DRONE_JOB_UUID': 'b3f0c7f6bb'}, globalenv=globalenv),
   linux_cxx("Clang 4.0", "clang++-4.0", packages="clang-4.0 libstdc++-6-dev", llvm_os="xenial", llvm_ver="4.0", buildtype="boost", buildscript="drone", image="cppalliance/droneubuntu1604:1", environment={'B2_TOOLSET': 'clang-4.0', 'B2_CXXSTD': '11,14', 'DRONE_JOB_UUID': '91032ad7bb'}, globalenv=globalenv),
-  linux_cxx("Clang 5.0", "clang++-5.0", packages="clang-5.0 libstdc++-7-dev", llvm_os="bionic", llvm_ver="5.0", buildtype="boost", buildscript="drone", image=linuxglobalimage, environment={'B2_TOOLSET': 'clang-5.0', 'B2_CXXSTD': '11,14', 'DRONE_JOB_UUID': '472b07b9fc'}, globalenv=globalenv),
+  linux_cxx("Clang 5.0", "clang++-5.0", packages="clang-5.0", buildtype="boost", buildscript="drone", image=linuxglobalimage, environment={'B2_TOOLSET': 'clang-5.0', 'B2_CXXSTD': '11,14', 'DRONE_JOB_UUID': '472b07b9fc'}, globalenv=globalenv),
   linux_cxx("Clang 6.0", "clang++-6.0", packages="clang-6.0 libc6-dbg libstdc++-8-dev", llvm_os="bionic", llvm_ver="6.0", buildtype="boost", buildscript="drone", image=linuxglobalimage, environment={'B2_TOOLSET': 'clang-6.0', 'B2_CXXSTD': '14,17', 'B2_FLAGS': 'warnings=extra warnings-as-errors=on linkflags=-lstdc++fs', 'DRONE_JOB_UUID': '12c6fc06c9'}, globalenv=globalenv),
   linux_cxx("Clang 7", "clang++-7", packages="clang-7 libstdc++-8-dev", llvm_os="bionic", llvm_ver="7", buildtype="boost", buildscript="drone", image=linuxglobalimage, environment={'B2_TOOLSET': 'clang-7', 'B2_CXXSTD': '17,2a', 'B2_FLAGS': 'warnings=extra warnings-as-errors=on linkflags=-lstdc++fs', 'DRONE_JOB_UUID': 'd435a6cdd7'}, globalenv=globalenv),
   linux_cxx("Clang 8", "clang++-8", packages="clang-8 libstdc++-8-dev", llvm_os="bionic", llvm_ver="8", buildtype="boost", buildscript="drone", image=linuxglobalimage, environment={'B2_TOOLSET': 'clang-8', 'B2_CXXSTD': '17,2a', 'B2_FLAGS': 'warnings=extra warnings-as-errors=on linkflags=-lstdc++fs', 'DRONE_JOB_UUID': '4d134bc072'}, globalenv=globalenv),