Linux build failed with a strange linking issue. This error did not appear in the compilation of ICU, but in the link section of compiling PHP.

/usr/bin/ld: /home/jerry/static-php-cli-fork/buildroot/lib/libicuuc.a(udata.ao): in function `doLoadFromCommonData(signed char, char const*, char const*, char const*, char const*, char const*, char const*, char const*, signed char (*)(void*, char const*, char const*, UDataInfo const*), void*, UErrorCode*, UErrorCode*) [clone .constprop.0]':
udata.cpp:(.text._ZL20doLoadFromCommonDataaPKcS0_S0_S0_S0_S0_S0_PFaPvS0_S0_PK9UDataInfoES1_P10UErrorCodeS8_.constprop.0+0x38a): undefined reference to `icudt73_dat'
/usr/bin/ld: udata.cpp:(.text._ZL20doLoadFromCommonDataaPKcS0_S0_S0_S0_S0_S0_PFaPvS0_S0_PK9UDataInfoES1_P10UErrorCodeS8_.constprop.0+0x467): undefined reference to `icudt73_dat'
collect2: error: ld returned 1 exit status

I have attempted to change configure options but still not working.

<?php

declare(strict_types=1);

namespace SPC\builder\linux\library;

class icu extends LinuxLibraryBase
{
    public const NAME = 'icu';

    protected function build()
    {
        $root = BUILD_ROOT_PATH;
        $cppflag = 'CPPFLAGS="-DU_CHARSET_IS_UTF8=1  -DU_USING_ICU_NAMESPACE=1  -DU_STATIC_IMPLEMENTATION=1"';
        shell()->cd($this->source_dir . '/source')
            ->exec(
                "{$this->builder->configure_env} {$cppflag} ./runConfigureICU Linux " .
                '--enable-static ' .
                '--disable-shared ' .
                '--with-data-packaging=static ' .
                '--enable-release=yes ' .
                '--enable-extras=yes ' .
                '--enable-icuio=yes ' .
                '--enable-dyload=no ' .
                '--enable-tools=yes ' .
                '--enable-tests=no ' .
                '--enable-samples=no ' .
                "--prefix={$root}"
            )
            ->exec('make clean')
            ->exec("make -j{$this->builder->concurrency}")
            ->exec('make install');
    }
}

PR can be merged now, but only support macOS.

And don't forget sorting config:

bin/spc sort-config ext
bin/spc sort-config lib
bin/spc sort-config source

This error has been resolved via Stack Overflow. But a new error has appeared :(

Failed in sanity check: buildroot/bin/php --ri "intl" and after running, the terminal outputs half of the content, and then Aborted.

I checked it, it caused by C++. That means we can only build icu in alpine docker (like swoole).

Yeah, I just stumbled upon that Stack Overflow answer as well! 👍

Just for my understanding: is it a problem if this can only be built in alpine docker?

Thanks for letting me know about the sort-config commands and for already taking care of it.

Just for my understanding: is it a problem if this can only be built in alpine docker?

In linux, it is difficult to statically link libraries written in C++, especially when using glibc distributions. Alpine Linux uses musl-libc and its g++ is working well with static compilation (so far, it seems like this).