bb8e3f45a6
Ccache CMake build system has some conditions that automatically
enables a developer mode (sets CCACHE_DEV_MODE=ON). See [1].
More specifically, if CCACHE_DEV_MODE is unset AND the environment
variable "CI" is set, CCACHE_DEV_MODE is set to "ON".
This situation can happen when Buildroot builds are executed in
Jenkins jobs, for example. Since Buildroot does not set
CCACHE_DEV_MODE and Jenkins sets the "CI" environment variable,
this ccache developer mode can be enabled in an unexpected way
for the Buildroot user. For example, it happened that a Jenkins build
breaks, while the build with the same configuration in the user
session is working.
One of the effects of enabling this ccache developer mode, is to treat
compiler warnings as errors, see [3]. This can lead to build error,
depending on the ccache version and the host compiler being used.
This behavior can be reproduced and observed, with commands:
cat > .config <<EOF
BR2_aarch64=y
BR2_TOOLCHAIN_EXTERNAL=y
BR2_CCACHE=y
BR2_PACKAGE_BUSYBOX=y
EOF
make olddefconfig
make clean
make host-ccache
Outputs:
...
-- Ccache version: 4.9.1
-- Ccache dev mode: OFF
-- Setting CMAKE_BUILD_TYPE to Release as none was specified.
...
Whereas:
make clean
CI=true make host-ccache
Outputs:
...
-- Ccache version: 4.9.1
-- Ccache dev mode: ON
-- Setting CMAKE_BUILD_TYPE to Debug as none was specified.
...
For a failure example: on Fedora 40 with host gcc 14.1.1, Buildroot at
tag 2024.02 has ccache 4.8.2. Host ccache can fail, when building with
"CI=true make host-ccache" with output:
/buildroot/output/build/host-ccache-4.8.2/src/third_party/fmt/core.h:3119:44: in 'constexpr' expansion of 'fmt::v8::make_format_args<>(args#0, args#1)'
/buildroot/output/build/host-ccache-4.8.2/src/third_party/fmt/core.h:1706:15: error: possibly dangling reference to a temporary [-Werror=dangling-reference]
1706 | const auto& arg = arg_mapper<Context>().map(std::forward<T>(val));
| ^~~
This commit sets CCACHE_DEV_MODE=OFF to make the ccache behavior more
deterministic in Buildroot, independently of being used in a CI tool
or not.
[1] https://github.com/ccache/ccache/blob/v4.9.1/CMakeLists.txt#L56
[2] https://github.com/jenkinsci/jenkins/blob/jenkins-2.459/core/src/main/java/jenkins/model/CoreEnvironmentContributor.java#L43
[3] https://github.com/ccache/ccache/blob/v4.9.1/cmake/StandardWarnings.cmake#L5
Reported-by: Xavier Roumegue <xroumegue@gmail.com>
Signed-off-by: Julien Olivain <ju.o@free.fr>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
(cherry picked from commit
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| .github | ||
| arch | ||
| board | ||
| boot | ||
| configs | ||
| docs | ||
| fs | ||
| linux | ||
| package | ||
| support | ||
| system | ||
| toolchain | ||
| utils | ||
| .checkpackageignore | ||
| .clang-format | ||
| .defconfig | ||
| .editorconfig | ||
| .flake8 | ||
| .gitignore | ||
| .gitlab-ci.yml | ||
| .shellcheckrc | ||
| CHANGES | ||
| Config.in | ||
| Config.in.legacy | ||
| COPYING | ||
| DEVELOPERS | ||
| Makefile | ||
| Makefile.legacy | ||
| README | ||
Buildroot is a simple, efficient and easy-to-use tool to generate embedded Linux systems through cross-compilation. The documentation can be found in docs/manual. You can generate a text document with 'make manual-text' and read output/docs/manual/manual.text. Online documentation can be found at http://buildroot.org/docs.html To build and use the buildroot stuff, do the following: 1) run 'make menuconfig' 2) select the target architecture and the packages you wish to compile 3) run 'make' 4) wait while it compiles 5) find the kernel, bootloader, root filesystem, etc. in output/images You do not need to be root to build or run buildroot. Have fun! Buildroot comes with a basic configuration for a number of boards. Run 'make list-defconfigs' to view the list of provided configurations. Please feed suggestions, bug reports, insults, and bribes back to the buildroot mailing list: buildroot@buildroot.org You can also find us on #buildroot on OFTC IRC. If you would like to contribute patches, please read https://buildroot.org/manual.html#submitting-patches