[mobile] Skip RoundTrip_AllWindowLogs compression tests on mobile platforms

[github-actions]

Reasoning

Three compression encoder/decoder tests are failing consistently across all mobile platforms (iOS, tvOS, macCatalyst, Android) in the runtime-extra-platforms pipeline:

• DeflateEncoderDecoderTests.RoundTrip_AllWindowLogs
• ZLibEncoderDecoderTests.RoundTrip_AllWindowLogs
• GZipEncoderDecoderTests.RoundTrip_AllWindowLogs

All three tests fail with the same assertion error: the encoder's Compress operation returns OperationStatus.DestinationTooSmall instead of OperationStatus.Done when testing with various window log sizes. The test allocates a destination buffer using GetMaxCompressedLength(input.Length) and expects compression to complete in a single call, but the buffer size is insufficient on mobile platforms.

This PR adds [ActiveIssue] attributes to skip these tests on mobile platforms until the underlying product bug is fixed. The issue affects all compression formats (Deflate, ZLib, GZip) and all mobile architectures.

Impact on platforms

Failing on all mobile platforms and architectures in build 1406427 (2026-05-03):

• maccatalyst-x64 / OSX.15.Amd64.Open / exit code 1
• maccatalyst-arm64 / OSX.15.Arm64.Open / exit code 1
• iossimulator-x64 / OSX.15.Amd64.Open / exit code 1
• iossimulator-arm64 / OSX.15.Arm64.Open / exit code 1
• tvos-arm64 / osx.15.amd64.appletv.open / exit code 1
• android-arm64 / Windows.11.Amd64.Android.Open / exit code 1
• android-arm / Windows.11.Amd64.Android.Open / exit code 1
• android-x64 / Windows.11.Amd64.Android.Open / exit code 1
• android-x86 / Windows.11.Amd64.Android.Open / exit code 1

Errors log

From maccatalyst-x64 Helix work item System.IO.Compression.Tests:

[FAIL] System.IO.Compression.DeflateEncoderDecoderTests.RoundTrip_AllWindowLogs
Assert.Equal() Failure: Values differ
Expected: Done
Actual:   DestinationTooSmall
   at System.IO.Compression.EncoderDecoderTestBase.RoundTrip_AllWindowLogs()

[FAIL] System.IO.Compression.ZLibEncoderDecoderTests.RoundTrip_AllWindowLogs  
Assert.Equal() Failure: Values differ
Expected: Done
Actual:   DestinationTooSmall
   at System.IO.Compression.EncoderDecoderTestBase.RoundTrip_AllWindowLogs()

[FAIL] System.IO.Compression.GZipEncoderDecoderTests.RoundTrip_AllWindowLogs
Assert.Equal() Failure: Values differ
Expected: Done
Actual:   DestinationTooSmall
   at System.IO.Compression.EncoderDecoderTestBase.RoundTrip_AllWindowLogs()

First build it occurred

First observed (within the scanned window of ~20 builds) in build 1399212, which finished on 2026-04-28T07:31:50Z. The failure has been present in every subsequent build.

Occurrences in scanned window: 100% failure rate for these tests on all mobile platforms.

Fixes #127563

Note

🔒 Integrity filter blocked 3 items

The following items were blocked because they don't meet the GitHub integrity level.

• #112656 search_issues: has lower integrity than agent requires. The agent cannot read data with integrity below "approved".
• #122358 search_issues: has lower integrity than agent requires. The agent cannot read data with integrity below "approved".
• #19443 search_issues: has lower integrity than agent requires. The agent cannot read data with integrity below "approved".

To allow these resources, lower min-integrity in your GitHub frontmatter:

tools:
  github:
    min-integrity: approved  # merged | approved | unapproved | none

Generated by Mobile Platform Failure Scanner · ● 5.2M · ◷

[dotnet-policy-service]

Tagging subscribers to this area: @karelz, @dotnet/area-system-io-compression
See info in area-owners.md if you want to be subscribed.

[jkotas]

Duplicate #127789