brew update shows deleted software

[Kha1r0]

Output of brew config

HOMEBREW_VERSION: 4.4.3
ORIGIN: https://github.com/Homebrew/brew
HEAD: 91f3671b16fe62121364c465c14e0dfd088d7ead
Last commit: 2 days ago
Core tap JSON: 29 Oct 22:40 UTC
Core cask tap JSON: 29 Oct 22:40 UTC
HOMEBREW_PREFIX: /opt/homebrew
HOMEBREW_CASK_OPTS: []
HOMEBREW_MAKE_JOBS: 10
Homebrew Ruby: 3.3.5 => /opt/homebrew/Library/Homebrew/vendor/portable-ruby/3.3.5/bin/ruby
CPU: 10-core 64-bit arm_blizzard_avalanche
Clang: 16.0.0 build 1600
Git: 2.47.0 => /opt/homebrew/bin/git
Curl: 8.7.1 => /usr/bin/curl
macOS: 15.0.1-arm64
CLT: 16.0.0.0.1.1724870825
Xcode: N/A
Rosetta 2: false

Output of brew doctor

Your system is ready to brew.

Description of issue

After running brew update, i get the message that icu4c is deleted from the repository. Does that mean my device is running unmaintained, possibly insecure software? Do i have reason to be worried?

[p-linnane]

No, we just versioned icu4c. If you run brew info icu4c you will see it is now an alias to icu4c@75.

[Kha1r0]

Thanks! How do i know I‘m safe if i see a message like this in the future? Sorry if this is a stupid question.

[p-linnane]

If you run brew doctor it will let you know if you are using discontinued software:

Warning: Some installed formulae are deprecated or disabled.
You should find replacements for the following formulae:
  cowsay

[Kha1r0]

Thank you! ❤️

[tobbi]

@p-linnane For me it also automatically uninstalled icu4c with that message. However, there were formulas that depended on icu4c that now failed to build.

In my case, libxml2:

==> Upgrading libxml2
  2.13.4_2 -> 2.13.4_3
==> ./configure --sysconfdir=/usr/local/etc --disable-silent-rules --with-history --with-http --with-icu --without-python --without-lzma
==> make install
Last 15 lines from /Users/tobiasmarkus/Library/Logs/Homebrew/libxml2/02.make:
      _xmlFindExtraHandler in libxml2_la-encoding.o
      _xmlCharEncCloseFunc in libxml2_la-encoding.o
      _openIcuConverter in libxml2_la-encoding.o
  "_ucnv_convertEx_76", referenced from:
      _xmlUconvWrapper in libxml2_la-encoding.o
  "_ucnv_open_76", referenced from:
      _openIcuConverter in libxml2_la-encoding.o
  "_ucnv_setFromUCallBack_76", referenced from:
      _openIcuConverter in libxml2_la-encoding.o
  "_ucnv_setToUCallBack_76", referenced from:
      _openIcuConverter in libxml2_la-encoding.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make[1]: *** [libxml2.la] Error 1

[EricFromCanada]

The missing symbols are in libicuuc.76.dylib:

$ nm -gU /opt/homebrew/opt/icu4c@76/lib/libicuuc.76.dylib | grep _ucnv_setToUCallBack_76
0000000000065868 T _ucnv_setToUCallBack_76

On ARM w/ Sonoma this library is linked to:

$ brew linkage libxml2
System libraries:
  /usr/lib/libSystem.B.dylib
  /usr/lib/libiconv.2.dylib
  /usr/lib/libncurses.5.4.dylib
  /usr/lib/libz.1.dylib
Homebrew libraries:
  /opt/homebrew/opt/icu4c@76/lib/libicudata.76.dylib (icu4c@76)
  /opt/homebrew/opt/icu4c@76/lib/libicui18n.76.dylib (icu4c@76)
  /opt/homebrew/opt/icu4c@76/lib/libicuuc.76.dylib (icu4c@76)
  /opt/homebrew/Cellar/libxml2/2.13.4_4/lib/libxml2.2.dylib (libxml2)
  /opt/homebrew/opt/readline/lib/libhistory.8.dylib (readline)
  /opt/homebrew/opt/readline/lib/libreadline.8.dylib (readline)

which we can see when building from source:

/bin/sh ./libtool  --tag=CC   --mode=link clang -pedantic -Wall -Wextra -Wshadow -Wpointer-arith 
…
libxml2_la-xpointer.lo -liconv -L/opt/homebrew/Cellar/icu4c/74.2/lib -licui18n -licuuc -licudata

while on Intel w/ Monterey, -licuuc -licudata are missing:

/bin/sh ./libtool  --tag=CC   --mode=link clang -pedantic -Wall -Wextra -Wshadow -Wpointer-arith
…
libxml2_la-xpointer.lo -L/usr/lib -lz -L/usr/local/Cellar/icu4c@76/76.1_1/lib -licui18n  -liconv

[ZhongRuoyu]

I encountered this a while back too. I haven't had the chance to submit the fix upstream, but I believe this is because libxml2's pkg-config check for icu is missing icu-uc:

    # Try pkg-config first so that static linking works.
    # If this succeeeds, we ignore the WITH_ICU directory.
    PKG_CHECK_MODULES([ICU], [icu-i18n], [
        WITH_ICU=1; XML_PC_REQUIRES="${XML_PC_REQUIRES} icu-i18n"
        m4_ifdef([PKG_CHECK_VAR],
            [PKG_CHECK_VAR([ICU_DEFS], [icu-i18n], [DEFS])])
        if test "x$ICU_DEFS" != "x"; then
            ICU_CFLAGS="$ICU_CFLAGS $ICU_DEFS"
        fi],[:])

We were able to build this in Homebrew CI because pkg-config happened to be absent in the dep tree.

Their CMake counterpart is good:

if(LIBXML2_WITH_ICU)
    find_package(ICU REQUIRED COMPONENTS data i18n uc)
endif()

[EricFromCanada]

Just confirmed that first running brew uninstall pkg-config allows brew install libxml2 to succeed on platforms without bottles. Thanks!

[ZhongRuoyu]

Upstreamed a patch: https://gitlab.gnome.org/GNOME/libxml2/-/merge_requests/289. Also fixing this at Homebrew/homebrew-core#197591.

[ZhongRuoyu]

Update: Homebrew's libxml2 has been fixed. It's now possible to build libxml2 without the pkg-config workaround.