[MacPorts] #62548: Universal variant for icu, which many ports depend on, doesn't work

[MacPorts]

#62548: Universal variant for icu, which many ports depend on, doesn't work
-----------------------+--------------------
 Reporter:  CharlesJS  |      Owner:  (none)
     Type:  defect     |     Status:  new
 Priority:  Normal     |  Milestone:
Component:  ports      |    Version:
 Keywords:             |       Port:
-----------------------+--------------------
 Many ports depend on the `icu` port. Unfortunately, its universal build
 does not work.

 When trying to build a dependent port:

 ```
 $ sudo port install gnutls +universal
 Warning: The macOS 11.2 SDK does not appear to be installed. Ports may not
 build correctly.
 Warning: You can install it as part of the Xcode Command Line Tools
 package by running `xcode-select --install'.
 --->  Computing dependencies for gnutls
 Error: Cannot install libxslt for the archs 'arm64 x86_64' because
 Error: its dependency icu cannot build for the required archs.
 Error: Follow https://guide.macports.org/#project.tickets to report a bug.
 Error: Processing of port gnutls failed
 ```

 But:

 ```
 $ port variants icu
 icu has the variants:
    universal: Build for multiple architectures
 ```

 And yet:
 ```
 $ sudo port install icu +universal
 --->  Fetching archive for icu
 --->  Attempting to fetch icu-67.1_3.darwin_20.x86_64.tbz2 from
 https://pek.cn.packages.macports.org/macports/packages/icu
 --->  Attempting to fetch icu-67.1_3.darwin_20.x86_64.tbz2.rmd160 from
 https://pek.cn.packages.macports.org/macports/packages/icu
 --->  Installing icu @67.1_3
 --->  Activating icu @67.1_3
 --->  Cleaning icu
 --->  Updating database of binaries
 --->  Scanning binaries for linking errors
 --->  No broken files found.
 --->  No broken ports found.

 $ file /opt/local/lib/libicudata.dylib
 /opt/local/lib/libicudata.dylib: Mach-O 64-bit dynamically linked shared
 library x86_64
 ```

-- 
Ticket URL: <https://trac.macports.org/ticket/62548>
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