Fix build with ICU 76

[cho-m]

Due to unicode-org/icu@199bc82, ICU 76 no longer adds icu-uc by default. This causes linker errors for undefined symbols like icu_76::UnicodeString::doReplace(...), referenced from: zim::removeAccents(...) in tools.cpp.o.

Meson will automatically flatten the dependencies list as documented at https://mesonbuild.com/Reference-manual_functions.html#build_target

---

There didn't seem to be any usage of icu_dep methods and only passing it to dependencies: [..., icu_dep, ...]. If this changes, then may need to use multiple variables.

[cho-m]

Linux CI has an unrelated failure trying to find software-properties-common which isn't available in Debian Trixie.

---

Windows CI has a related failure as it looks like icu-i18n.pc is manually created.

Maybe a workaround like:

dependency('icu-uc', required: host_machine.system() != 'windows', static:static_linkage)

or

icu_dep = [dependency('icu-i18n', required:xapian_dep.found(), static:static_linkage)]
if build_machine.system() != 'windows'
    icu_dep += [dependency('icu-uc', required:xapian_dep.found(), static:static_linkage)]
endif

[kelson42]

@cho-m Thank you for your PR. CI was OK a month ago, I will have a look and try to fix them so we can test your PR properly.

[kelson42]

@cho-m I have fixed a few things but we have a serious problem with the Windows CI. The CI for Windows does not pass for the moment on main either... although it does not block at the line you have added. My that be that your code is not compatible with older version of libicu? https://github.com/kiwix/kiwix-build/blob/main/kiwixbuild/dependencies/icu4c.py

[cho-m]

code is not compatible with older version of libicu? https://github.com/kiwix/kiwix-build/blob/main/kiwixbuild/dependencies/icu4c.py

The official (Unix) pkgconfig files are compatible (icu-uc.pc has been around as long as icu-i18n.pc, i.e. ICU 59 - https://github.com/unicode-org/icu/commit/d39075895576f183ef9756aabe34db8b64e6af38)

However, Windows build is using custom/3rd-party pkgconfig files. Ideally would have provided other pkgconfig files like Cygwin (https://cygwin.com/packages/x86_64/libicu-devel/libicu-devel-73.2-1)

    2023-08-03 01:02        1232 usr/lib/pkgconfig/icu-i18n.pc
    2023-08-03 01:02        1224 usr/lib/pkgconfig/icu-io.pc
    2023-08-03 01:02        1256 usr/lib/pkgconfig/icu-uc.pc

---

Anyways, PR most likely needs a build_machine.system() != 'windows' conditional to work around Windows.

[kelson42]

@veloman-yunkan @cho-m I can not merge this PR right now because it brakes the CI on Windows. From what I understand, I see only one way to solve this (and just ignoring Windows seems a dirty fix). Open an issue in kiwix/kiwix-build and fix how we deal with libicu on Windows there. Seems anyway pretty much linked to https://github.com/kiwix/kiwix-build/issues/750 which seems to be a blocker for that PR then. Do I'm correct?

[veloman-yunkan]

@kelson42 I am fine with that.

[cho-m]

From what I understand, I see only one way to solve this (and just ignoring Windows seems a dirty fix).

Could do a version check - https://mesonbuild.com/Reference-manual_returned_dep.html#depversion

Maybe something like:

icu_dep = dependency('icu-i18n', static:static_linkage)
if icu_dep.version().version_compare('>= 76')
  icu_dep = [icu_dep, dependency('icu-uc', static:static_linkage)]
endif

[hashworks]

I've included a 9.1.0 variant of this patch in the Arch Linux icu76 rebuild.

[shenlebantongying]

Also included in Nix btw

https://github.com/NixOS/nixpkgs/pull/385849

[codecov[bot]]

Codecov Report

:white_check_mark: All modified and coverable lines are covered by tests. :white_check_mark: Project coverage is 58.13%. Comparing base (1db4abe) to head (a03846b). :warning: Report is 3 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #936   +/-   ##
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  Coverage   58.13%   58.13%           
=======================================
  Files         101      101           
  Lines        5384     5384           
  Branches     2197     2197           
=======================================
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  Misses        795      795           
  Partials     1459     1459           

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[kelson42]

@cho-m Please

From what I understand, I see only one way to solve this (and just ignoring Windows seems a dirty fix).

Could do a version check - https://mesonbuild.com/Reference-manual_returned_dep.html#depversion

Maybe something like:

icu_dep = dependency('icu-i18n', static:static_linkage)
if icu_dep.version().version_compare('>= 76')
  icu_dep = [icu_dep, dependency('icu-uc', static:static_linkage)]
endif

@cho-m Please do and rerequest review

[kelson42]

@cho-m Any feedback or have you abandoned this PR?

[kelson42]

Supersseded by #1010 (same code, just with the libicu version condition proposed by @cho-m)

@shenlebantongying @hashworks So, will finally be part of the soon to be released libzim 9.4.0. If everything goes right you should not need anymore your custom patches.