InvalidDataException (unsupported compression method) when restoring extension

[christianfredh]

Bicep version
bicep --version: Bicep CLI version 0.41.2 (3e403ea)
az bicep version: Bicep CLI version 0.41.2 (3e403ea)
dotnet --version: 10.0.103

Describe the bug
Getting Unhandled exception. System.IO.InvalidDataException: The archive entry was compressed using an unsupported compression method. trying to restore extension.

To Reproduce
main.bicep

extension 'bicepconfig.json'

bicepconfig.json

{
  "extensions": {
    "microsoftGraphV1": "br:mcr.microsoft.com/bicep/extensions/microsoftgraph/v1.0:1.0.0"
  }
}

Run:
bicep restore main.bicep

Getting:

Unhandled exception. System.IO.InvalidDataException: The archive entry was compressed using an unsupported compression method.
   at System.IO.Compression.Inflater.Inflate(FlushCode flushCode)
   at System.IO.Compression.Inflater.ReadInflateOutput(Byte* bufPtr, Int32 length, FlushCode flushCode, Int32& bytesRead)
   at System.IO.Compression.Inflater.ReadOutput(Byte* bufPtr, Int32 length, Int32& bytesRead)
   at System.IO.Compression.Inflater.InflateVerified(Byte* bufPtr, Int32 length)
   at System.IO.Compression.Inflater.Inflate(Span`1 destination)
   at System.IO.Compression.DeflateStream.ReadCore(Span`1 buffer)
   at System.IO.Compression.GZipStream.Read(Span`1 buffer)
   at System.IO.Stream.ReadAtLeastCore(Span`1 buffer, Int32 minimumBytes, Boolean throwOnEndOfStream)
   at System.IO.Stream.ReadExactly(Span`1 buffer)
   at System.Formats.Tar.TarHeader.TryGetNextHeader(Stream archiveStream, Boolean copyData, TarEntryFormat initialFormat, Boolean processDataBlock)
   at System.Formats.Tar.TarReader.TryGetNextEntryHeader(Boolean copyData)
   at System.Formats.Tar.TarReader.GetNextEntry(Boolean copyData)
   at Bicep.Core.Registry.Extensions.ExtensionV1Archive.Read(BinaryData binaryData)
   at Bicep.Core.Registry.LocalModuleRegistry.RestoreArtifacts(IEnumerable`1 references)
   at Bicep.Core.Registry.ModuleDispatcher.RestoreArtifacts(IEnumerable`1 references, Boolean forceRestore)
   at Bicep.Core.BicepCompiler.Restore(Compilation compilation, Boolean forceRestore)
   at Bicep.Cli.Commands.RestoreCommand.Restore(IOUri inputUri, Boolean force)
   at Bicep.Cli.Commands.RestoreCommand.RunAsync(RestoreArguments args)
   at Bicep.Cli.Program.RunAsync(String[] args, CancellationToken cancellationToken)
   at Bicep.Cli.Program.<>c__DisplayClass3_0.<<Main>b__0>d.MoveNext()
--- End of stack trace from previous location ---
   at Bicep.Cli.Program.RunWithCancellationAsync(Func`2 runFunc)
   at Bicep.Cli.Program.Main(String[] args)
   at Bicep.Cli.Program.<Main>(String[] args)

Or run:
az bicep restore --file main.bicep --force --debug

Getting:

cli.knack.cli: Command arguments: ['bicep', 'restore', '--file', 'main.bicep', '--force', '--debug']
cli.knack.cli: __init__ debug log:
Enable color in terminal.
cli.knack.cli: Event: Cli.PreExecute []
cli.knack.cli: Event: CommandParser.OnGlobalArgumentsCreate [<function CLILogging.on_global_arguments at 0x10945cae0>, <function OutputProducer.on_global_arguments at 0x10962eb60>, <function CLIQuery.on_global_arguments at 0x109674f40>]
cli.knack.cli: Event: CommandInvoker.OnPreCommandTableCreate []
cli.azure.cli.core: Modules found from index for 'bicep': ['azure.cli.command_modules.resource']
cli.azure.cli.core: Loading command modules:
cli.azure.cli.core: Name                  Load Time    Groups  Commands
cli.azure.cli.core: resource                  0.127        52       234
cli.azure.cli.core: Total (1)                 0.127        52       234
cli.azure.cli.core: These extensions are not installed and will be skipped: ['azext_ai_examples', 'azext_next']
cli.azure.cli.core: Loading extensions:
cli.azure.cli.core: Name                  Load Time    Groups  Commands  Directory
cli.azure.cli.core: Total (0)                 0.000         0         0  
cli.azure.cli.core: Loaded 52 groups, 234 commands.
cli.azure.cli.core: Found a match in the command table.
cli.azure.cli.core: Raw command  : bicep restore
cli.azure.cli.core: Command table: bicep restore
cli.knack.cli: Event: CommandInvoker.OnPreCommandTableTruncate [<function AzCliLogging.init_command_file_logging at 0x10a486de0>]
cli.azure.cli.core.azlogging: metadata file logging enabled - writing logs to '/Users/<user>/.azure/commands/2026-03-09.16-24-22.bicep_restore.67397.log'.
az_command_data_logger: command args: bicep restore --file {} --force --debug
cli.knack.cli: Event: CommandInvoker.OnPreArgumentLoad [<function register_global_subscription_argument.<locals>.add_subscription_parameter at 0x10a4d0720>]
cli.knack.cli: Event: CommandInvoker.OnPostArgumentLoad []
cli.knack.cli: Event: CommandInvoker.OnPostCommandTableCreate [<function register_ids_argument.<locals>.add_ids_arguments at 0x10a4d2a20>, <function register_cache_arguments.<locals>.add_cache_arguments at 0x10a4d2c00>, <function register_upcoming_breaking_change_info.<locals>.update_breaking_change_info at 0x10a4d2ca0>]
cli.knack.cli: Event: CommandInvoker.OnCommandTableLoaded []
cli.knack.cli: Event: CommandInvoker.OnPreParseArgs []
cli.knack.cli: Event: CommandInvoker.OnPostParseArgs [<function OutputProducer.handle_output_argument at 0x10962ec00>, <function CLIQuery.handle_query_parameter at 0x109674fe0>, <function register_ids_argument.<locals>.parse_ids_arguments at 0x10a4d2ac0>]
cli.azure.cli.command_modules.resource._bicep: Current value of "use_binary_from_path": false.
cli.azure.cli.command_modules.resource._bicep: Current value of "use_binary_from_path": false.
cli.azure.cli.command_modules.resource._bicep: Current value of "use_binary_from_path": false.
cli.azure.cli.command_modules.resource._bicep: Bicep CLI installation path: /Users/<user>/.azure/bin/bicep
cli.azure.cli.command_modules.resource._bicep: Bicep CLI installed: True.
cli.azure.cli.core.azclierror: Traceback (most recent call last):
  File "/opt/homebrew/Cellar/azure-cli/2.78.0/libexec/lib/python3.13/site-packages/azure/cli/command_modules/resource/_bicep.py", line 370, in _run_command
    process.check_returncode()
    ~~~~~~~~~~~~~~~~~~~~~~~~^^
  File "/opt/homebrew/Cellar/python@3.13/3.13.9_1/Frameworks/Python.framework/Versions/3.13/lib/python3.13/subprocess.py", line 508, in check_returncode
    raise CalledProcessError(self.returncode, self.args, self.stdout,
                             self.stderr)
subprocess.CalledProcessError: Command '['/Users/<user>/.azure/bin/bicep', 'restore', 'main.bicep', '--force']' died with <Signals.SIGABRT: 6>.

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/opt/homebrew/Cellar/azure-cli/2.78.0/libexec/lib/python3.13/site-packages/knack/cli.py", line 233, in invoke
    cmd_result = self.invocation.execute(args)
  File "/opt/homebrew/Cellar/azure-cli/2.78.0/libexec/lib/python3.13/site-packages/azure/cli/core/commands/__init__.py", line 666, in execute
    raise ex
  File "/opt/homebrew/Cellar/azure-cli/2.78.0/libexec/lib/python3.13/site-packages/azure/cli/core/commands/__init__.py", line 734, in _run_jobs_serially
    results.append(self._run_job(expanded_arg, cmd_copy))
                   ~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/homebrew/Cellar/azure-cli/2.78.0/libexec/lib/python3.13/site-packages/azure/cli/core/commands/__init__.py", line 703, in _run_job
    result = cmd_copy(params)
  File "/opt/homebrew/Cellar/azure-cli/2.78.0/libexec/lib/python3.13/site-packages/azure/cli/core/commands/__init__.py", line 336, in __call__
    return self.handler(*args, **kwargs)
           ~~~~~~~~~~~~^^^^^^^^^^^^^^^^^
  File "/opt/homebrew/Cellar/azure-cli/2.78.0/libexec/lib/python3.13/site-packages/azure/cli/core/commands/command_operation.py", line 120, in handler
    return op(**command_args)
  File "/opt/homebrew/Cellar/azure-cli/2.78.0/libexec/lib/python3.13/site-packages/azure/cli/command_modules/resource/custom.py", line 4189, in restore_bicep_file
    run_bicep_command(cmd.cli_ctx, args)
    ~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^
  File "/opt/homebrew/Cellar/azure-cli/2.78.0/libexec/lib/python3.13/site-packages/azure/cli/command_modules/resource/_bicep.py", line 114, in run_bicep_command
    return _run_command(installation_path, args, custom_env)
  File "/opt/homebrew/Cellar/azure-cli/2.78.0/libexec/lib/python3.13/site-packages/azure/cli/command_modules/resource/_bicep.py", line 386, in _run_command
    raise UnclassifiedUserFault(error_msg)
azure.cli.core.azclierror.UnclassifiedUserFault: Unhandled exception. System.IO.InvalidDataException: The archive entry was compressed using an unsupported compression method.
   at System.IO.Compression.Inflater.Inflate(FlushCode flushCode)
   at System.IO.Compression.Inflater.ReadInflateOutput(Byte* bufPtr, Int32 length, FlushCode flushCode, Int32& bytesRead)
   at System.IO.Compression.Inflater.ReadOutput(Byte* bufPtr, Int32 length, Int32& bytesRead)
   at System.IO.Compression.Inflater.InflateVerified(Byte* bufPtr, Int32 length)
   at System.IO.Compression.Inflater.Inflate(Span`1 destination)
   at System.IO.Compression.DeflateStream.ReadCore(Span`1 buffer)
   at System.IO.Compression.GZipStream.Read(Span`1 buffer)
   at System.IO.Stream.ReadAtLeastCore(Span`1 buffer, Int32 minimumBytes, Boolean throwOnEndOfStream)
   at System.IO.Stream.ReadExactly(Span`1 buffer)
   at System.Formats.Tar.TarHeader.TryGetNextHeader(Stream archiveStream, Boolean copyData, TarEntryFormat initialFormat, Boolean processDataBlock)
   at System.Formats.Tar.TarReader.TryGetNextEntryHeader(Boolean copyData)
   at System.Formats.Tar.TarReader.GetNextEntry(Boolean copyData)
   at Bicep.Core.Registry.Extensions.ExtensionV1Archive.Read(BinaryData binaryData)
   at Bicep.Core.Registry.LocalModuleRegistry.RestoreArtifacts(IEnumerable`1 references)
   at Bicep.Core.Registry.ModuleDispatcher.RestoreArtifacts(IEnumerable`1 references, Boolean forceRestore)
   at Bicep.Core.BicepCompiler.Restore(Compilation compilation, Boolean forceRestore)
   at Bicep.Cli.Commands.RestoreCommand.Restore(IOUri inputUri, Boolean force)
   at Bicep.Cli.Commands.RestoreCommand.RunAsync(RestoreArguments args)
   at Bicep.Cli.Program.RunAsync(String[] args, CancellationToken cancellationToken)
   at Bicep.Cli.Program.<>c__DisplayClass3_0.<<Main>b__0>d.MoveNext()
--- End of stack trace from previous location ---
   at Bicep.Cli.Program.RunWithCancellationAsync(Func`2 runFunc)
   at Bicep.Cli.Program.Main(String[] args)
   at Bicep.Cli.Program.<Main>(String[] args)

cli.azure.cli.core.azclierror: Unhandled exception. System.IO.InvalidDataException: The archive entry was compressed using an unsupported compression method.
   at System.IO.Compression.Inflater.Inflate(FlushCode flushCode)
   at System.IO.Compression.Inflater.ReadInflateOutput(Byte* bufPtr, Int32 length, FlushCode flushCode, Int32& bytesRead)
   at System.IO.Compression.Inflater.ReadOutput(Byte* bufPtr, Int32 length, Int32& bytesRead)
   at System.IO.Compression.Inflater.InflateVerified(Byte* bufPtr, Int32 length)
   at System.IO.Compression.Inflater.Inflate(Span`1 destination)
   at System.IO.Compression.DeflateStream.ReadCore(Span`1 buffer)
   at System.IO.Compression.GZipStream.Read(Span`1 buffer)
   at System.IO.Stream.ReadAtLeastCore(Span`1 buffer, Int32 minimumBytes, Boolean throwOnEndOfStream)
   at System.IO.Stream.ReadExactly(Span`1 buffer)
   at System.Formats.Tar.TarHeader.TryGetNextHeader(Stream archiveStream, Boolean copyData, TarEntryFormat initialFormat, Boolean processDataBlock)
   at System.Formats.Tar.TarReader.TryGetNextEntryHeader(Boolean copyData)
   at System.Formats.Tar.TarReader.GetNextEntry(Boolean copyData)
   at Bicep.Core.Registry.Extensions.ExtensionV1Archive.Read(BinaryData binaryData)
   at Bicep.Core.Registry.LocalModuleRegistry.RestoreArtifacts(IEnumerable`1 references)
   at Bicep.Core.Registry.ModuleDispatcher.RestoreArtifacts(IEnumerable`1 references, Boolean forceRestore)
   at Bicep.Core.BicepCompiler.Restore(Compilation compilation, Boolean forceRestore)
   at Bicep.Cli.Commands.RestoreCommand.Restore(IOUri inputUri, Boolean force)
   at Bicep.Cli.Commands.RestoreCommand.RunAsync(RestoreArguments args)
   at Bicep.Cli.Program.RunAsync(String[] args, CancellationToken cancellationToken)
   at Bicep.Cli.Program.<>c__DisplayClass3_0.<<Main>b__0>d.MoveNext()
--- End of stack trace from previous location ---
   at Bicep.Cli.Program.RunWithCancellationAsync(Func`2 runFunc)
   at Bicep.Cli.Program.Main(String[] args)
   at Bicep.Cli.Program.<Main>(String[] args)
az_command_data_logger: Unhandled exception. System.IO.InvalidDataException: The archive entry was compressed using an unsupported compression method.
   at System.IO.Compression.Inflater.Inflate(FlushCode flushCode)
   at System.IO.Compression.Inflater.ReadInflateOutput(Byte* bufPtr, Int32 length, FlushCode flushCode, Int32& bytesRead)
   at System.IO.Compression.Inflater.ReadOutput(Byte* bufPtr, Int32 length, Int32& bytesRead)
   at System.IO.Compression.Inflater.InflateVerified(Byte* bufPtr, Int32 length)
   at System.IO.Compression.Inflater.Inflate(Span`1 destination)
   at System.IO.Compression.DeflateStream.ReadCore(Span`1 buffer)
   at System.IO.Compression.GZipStream.Read(Span`1 buffer)
   at System.IO.Stream.ReadAtLeastCore(Span`1 buffer, Int32 minimumBytes, Boolean throwOnEndOfStream)
   at System.IO.Stream.ReadExactly(Span`1 buffer)
   at System.Formats.Tar.TarHeader.TryGetNextHeader(Stream archiveStream, Boolean copyData, TarEntryFormat initialFormat, Boolean processDataBlock)
   at System.Formats.Tar.TarReader.TryGetNextEntryHeader(Boolean copyData)
   at System.Formats.Tar.TarReader.GetNextEntry(Boolean copyData)
   at Bicep.Core.Registry.Extensions.ExtensionV1Archive.Read(BinaryData binaryData)
   at Bicep.Core.Registry.LocalModuleRegistry.RestoreArtifacts(IEnumerable`1 references)
   at Bicep.Core.Registry.ModuleDispatcher.RestoreArtifacts(IEnumerable`1 references, Boolean forceRestore)
   at Bicep.Core.BicepCompiler.Restore(Compilation compilation, Boolean forceRestore)
   at Bicep.Cli.Commands.RestoreCommand.Restore(IOUri inputUri, Boolean force)
   at Bicep.Cli.Commands.RestoreCommand.RunAsync(RestoreArguments args)
   at Bicep.Cli.Program.RunAsync(String[] args, CancellationToken cancellationToken)
   at Bicep.Cli.Program.<>c__DisplayClass3_0.<<Main>b__0>d.MoveNext()
--- End of stack trace from previous location ---
   at Bicep.Cli.Program.RunWithCancellationAsync(Func`2 runFunc)
   at Bicep.Cli.Program.Main(String[] args)
   at Bicep.Cli.Program.<Main>(String[] args)
cli.knack.cli: Event: Cli.PostExecute [<function AzCliLogging.deinit_cmd_metadata_logging at 0x10a487060>]
az_command_data_logger: exit code: 1
cli.__main__: Command ran in 1.333 seconds (init: 0.147, invoke: 1.186)
telemetry.main: Begin splitting cli events and extra events, total events: 1
telemetry.client: Accumulated 0 events. Flush the clients.
telemetry.main: Finish splitting cli events and extra events, cli events: 1
telemetry.save: Save telemetry record of length 5905 in cache file under /Users/<user>/.azure/telemetry/20260309162423896
telemetry.main: Begin creating telemetry upload process.
telemetry.process: Creating upload process: "/opt/homebrew/Cellar/azure-cli/2.78.0/libexec/bin/python /opt/homebrew/Cellar/azure-cli/2.78.0/libexec/lib/python3.13/site-packages/azure/cli/telemetry/__init__.py /Users/<user>/.azure /Users/<user>/.azure/telemetry/20260309162423896"
telemetry.process: Return from creating process 67422
telemetry.main: Finish creating telemetry upload process.

Additional context
OS: macOS Tahoe 26.2
(MacBook Pro M2)

[shenglol]

@christianfredh - It looks like you are trying to import an extension using the local file path bicepconfig.json. Bicep attempts to read the file as a tgz package, which results in the decompression error you are seeing.

To import the Graph extension defined in your Bicep configuration file, you should reference it by its extension name instead:

extension microsoftGraphV1

We will make sure the handle the exception and update the error message to make this clearer.

[christianfredh]

@christianfredh - It looks like you are trying to import an extension using the local file path bicepconfig.json. Bicep attempts to read the file as a tgz package, which results in the decompression error you are seeing.

To import the Graph extension defined in your Bicep configuration file, you should reference it by its extension name instead:

extension microsoftGraphV1

We will make sure the handle the exception and update the error message to make this clearer.

Ah yes, of course, that makes sense now. Sounds good, the error message could be a lot clearer, thank you!

Can't get the VSCode bicep extension work with extensions though, but I guess that is another issue, or not implemented. CLI seems to work fine after applying your comment.