ICU4C no longer builds with Cygwin (new version of Cygwin 3.0.0 causes build failures)

Description

This is a follow-up ticket/issue from ICU-20434.

From the previous ticket/issue:

It seems that Cygwin 3.0.0 was released on Saturday, Feb 16, and now the ICU4C AppVeyor CI builds are failing. (Previously, the AppVeyor builds used Cygwin 2.11.2-1.)

From the build output, it looks like pkgdata is failing with the following error:
Assembly type "-a gcc-mingw64" is unknown.

Log output:

Status

Assignee

Jeff Genovy

Reporter

Jeff Genovy

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Reviewer

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Time Needed

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Start date

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Fix versions

Priority

major
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