Rando ANDZA0000: Unable to open app.apk as a zip archive

[jonpryor]

It's our favorite, hysenbugs!

There is no repro!

Context:

• https://devdiv.visualstudio.com/DevDiv/_build/results?buildId=4935806&view=ms.vss-test-web.build-test-results-tab&runId=23180970&resultId=100203&paneView=attachments [note: will be invalid within a couple of weeks]
• https://discord.com/channels/732297728826277939/732297837953679412/860159968087113748
• …through…
• https://discord.com/channels/732297728826277939/732297837953679412/860236601267585076
• …and beyond…

Sometimes, the DebuggerAttribute"Full", False, True) unit test (and others?) will fail:

error ANDZA0000: Unable to open '/Users/runner/work/1/s/bin/TestRelease/temp/DebuggerAttribute_Full_False_True/obj/Debug/android/bin/com.xamarin.debuggerattribute.apk' as zip archive

The cause of the error is that zipalign doesn't like the file:

$ "$HOME/android-toolchain/sdk/build-tools/28.0.3/zipalign" -p 4 bin/Debug/com.xamarin.debuggerattribute.apk app-Signed.apk
Unable to open 'bin/Debug/com.xamarin.debuggerattribute.apk' as zip archive

The file does exist; it is attached here as com.xamarin.debuggerattribute.zip.

Aside: zipalign source: https://android.googlesource.com/platform/build.git/+/refs/heads/master/tools/zipalign/

Lots of spitballing and investigation later, and we we see that zipdetails -vv doesn't like it:

% zipdetails -vv com.xamarin.debuggerattribute.zip # or .apk…
…
00C06E 000004 50 4B 03 04 LOCAL HEADER #8       04034B50
00C072 000001 00          Extract Zip Spec      00 '0.0'
00C073 000001 00          Extract OS            00 'MS-DOS'
00C074 000002 00 00       General Purpose Flag  0000
00C076 000002 00 00       Compression Method    0000 'Stored'
00C078 000004 00 00 21 00 Last Mod Time         00210000 'Tue Jan  1 00:00:00 1980'
00C07C 000004 02 19 FA 61 CRC                   61FA1902
00C080 000004 BC 06 00 00 Compressed Length     000006BC
00C084 000004 BC 06 00 00 Uncompressed Length   000006BC
00C088 000002 0E 00       Filename Length       000E
00C08A 000002 02 00       Extra Length          0002
00C08C 00000E 72 65 73 6F Filename              'resources.arsc'
              75 72 63 65
              73 2E 61 72
              73 63
00C09A 000002 00 00       Malformed Extra Data  00 00
00C09C 0006BC ...         PAYLOAD


Unexpecded END at offset 0000C758, value 00000000
Done

It appears that either the resources.arsc entry, or the following classes.dex entry, is somehow broken; 7zip reports:

% 7z t -bb3 com.xamarin.debuggerattribute.apk
…
ERROR: Headers Error : classes.dex
…
Sub items Errors: 1

Archives with Errors: 1

Sub items Errors: 1

Something isn't kosher here.

@grendello eventually concludes:

local header for classes.dex is corrupted
the CD entry for it is fine
that's why listing the contents works fine
…
it appears the entry is preceded (or the previous entry followed) by two additional bytes
which then escalates to 9 extra bytes before the subsequent entries, but it appears to badly affect just the first entry with the extra leading bytes

It looks like this is due to something we're doing, but we're not sure what, why, or how to fix it.

[grendello]

Other ways to diagnose:

$ unzip -t com.xamarin.debuggerattribute.apk 
Archive:  com.xamarin.debuggerattribute.apk
    testing: AndroidManifest.xml      OK
    testing: res/drawable-mdpi-v4/icon.png   OK
    testing: res/drawable-hdpi-v4/icon.png   OK
    testing: res/drawable-xhdpi-v4/icon.png   OK
    testing: res/drawable-xxhdpi-v4/icon.png   OK
    testing: res/drawable-xxxhdpi-v4/icon.png   OK
    testing: res/layout/main.xml      OK
    testing: resources.arsc           OK
file #9:  bad zipfile offset (local header sig):  51032
    testing: lib/arm64-v8a/libxamarin-app.so   OK
    testing: lib/x86/libxamarin-app.so   OK
    testing: lib/arm64-v8a/libSystem.IO.Compression.Native.so   OK
    testing: lib/arm64-v8a/libSystem.Native.so   OK
    testing: lib/arm64-v8a/libSystem.Security.Cryptography.Native.Android.so   OK
    testing: lib/arm64-v8a/libmonosgen-2.0.so   OK
    testing: lib/arm64-v8a/libmonodroid.so   OK
    testing: lib/arm64-v8a/libxamarin-debug-app-helper.so   OK
    testing: lib/x86/libSystem.IO.Compression.Native.so   OK
    testing: lib/x86/libSystem.Native.so   OK
    testing: lib/x86/libSystem.Security.Cryptography.Native.Android.so   OK
    testing: lib/x86/libmonosgen-2.0.so   OK
    testing: lib/x86/libmonodroid.so   OK
    testing: lib/x86/libxamarin-debug-app-helper.so   OK
At least one error was detected in com.xamarin.debuggerattribute.apk.

unzip -t doesn't give name of the broken entry, alas.

zipinfo -vv shows us there are extra bytes preceding classes.dex (or following the previous entry, resources.arsc. @dellis1972 notes that the broken entry follows data we add to the apk by copying it from another zip archive creted by aapt2

Central directory entry #9:
---------------------------

  There are an extra 2 bytes preceding this file.

  classes.dex

  offset of local header from start of archive:   51032
                                                  (000000000000C758h) bytes
  file system or operating system of origin:      Unix
  version of encoding software:                   6.3
  minimum file system compatibility required:     MS-DOS, OS/2 or NT FAT
  minimum software version required to extract:   2.0
  compression method:                             deflated
  compression sub-type (deflation):               maximum
  file security status:                           not encrypted
  extended local header:                          no
  file last modified on (DOS date/time):          2021 Jul 1 08:50:32
  32-bit CRC value (hex):                         ec5ca9fd
  compressed size:                                72278 bytes
  uncompressed size:                              317776 bytes
  length of filename:                             11 characters
  length of extra field:                          0 bytes
  length of file comment:                         0 characters
  disk number on which file begins:               disk 1
  apparent file type:                             binary
  Unix file attributes (100644 octal):            -rw-r--r--
  MS-DOS file attributes (00 hex):                none

  There is no file comment.

Central directory entry #10:
---------------------------

  There are an extra 9 bytes preceding this file.

  lib/arm64-v8a/libxamarin-app.so

[jonpryor]

We have another apparent instance of this bug: https://devdiv.visualstudio.com/DevDiv/_build/results?buildId=4979360&view=ms.vss-test-web.build-test-results-tab&runId=23547392&resultId=100040&paneView=attachments

/Library/Frameworks/Mono.framework/External/xbuild/Xamarin/Android/Xamarin.Android.Common.targets(2320,2):
error ANDZA0000: Unable to open '…/CheckOldResourceDesignerWithWrongCasingIsRemoved(False)/obj/Debug/android/bin/com.xamarin.checkoldresourcedesignerwithwrongcasingisremoved.apk' as zip archive