utmpx.h is provided by this new release of the Android NDK, defining functions as nonfunctional as utmp.h does.
The more pressing problem is that its presence suppresses the definition of UTMP_NAME_FUNCTION when a program is built with an __ANDROID_API__ lower than 34, where the utmpx* series of functions were introduced, because the conditional for HAVE_UTMPX_H in readutmp.h does not search for a `utmpname' function if `utmpxname' is unavailable, with the result that get_android_boot_time is never invoked. Here are the relevant portions of config.log: configure:9462: checking for utmpx.h configure:9462: /opt/android/ndk/android-ndk-r26/toolchains/llvm/prebuilt/linux-x86_64/bin/aarch64-linux-android22-clang -c -O2 -g3 -Werror=implicit-function-declaration conftest.c >&5 configure:9462: $? = 0 configure:9462: result: yes configure:16416: /opt/android/ndk/android-ndk-r26/toolchains/llvm/prebuilt/linux-x86_64/bin/aarch64-linux-android22-clang -o conftest -O2 -g3 -Werror=implicit-function-declaration conftest.c >&5 ld.lld: error: undefined symbol: utmpxname >>> referenced by conftest.c:116 >>> /tmp/conftest-c4f4cf.o:(main) >>> did you mean: utmpname >>> defined in: >>> /opt/android/ndk/android-ndk-r26/toolchains/llvm/prebuilt/linux-x86_64/bin/../sysroot/usr/lib/aarch64-linux-android/22/libc.so I will install a workaround in Emacs, but it ought to be fixed at the source.
