fix: support Fable.Beam rc.37

[dbrattli]

Summary

• update Fable.Beam to 5.0.0-rc.37 in the main and test Paket groups
• migrate the BEAM logger to Fable.Beam's public curried Logger API
• avoid FSharp.Core's unsupported dynamic subtraction path when parsing named placeholders

Validation

• dotnet build test -m:1

• dotnet run --project test --no-build (51/51 passed)

• git diff --check

  Determining projects to restore...
  Paket version 10.3.1+bbc45f336c7f9bac95cf1d17267ab2383d029682
  Paket version 10.3.1+bbc45f336c7f9bac95cf1d17267ab2383d029682
  Paket version 10.3.1+bbc45f336c7f9bac95cf1d17267ab2383d029682
  The last full restore is still up to date. Nothing left to do.
  The last full restore is still up to date. Nothing left to do.
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  The last full restore is still up to date. Nothing left to do.
  Total time taken: 0 milliseconds
  Paket version 10.3.1+bbc45f336c7f9bac95cf1d17267ab2383d029682
  The last full restore is still up to date. Nothing left to do.
  Total time taken: 0 milliseconds
  All projects are up-to-date for restore.
  Fable.Logging -> /home/dbrattli/developer/Fable.Logging/src/Fable.Logging/bin/Debug/netstandard2.0/Fable.Logging.dll
  Fable.Logging.Beam -> /home/dbrattli/developer/Fable.Logging/src/Fable.Logging.Beam/bin/Debug/netstandard2.0/Fable.Logging.Beam.dll
  Fable.Logging.Structlog -> /home/dbrattli/developer/Fable.Logging/src/Fable.Logging.Structlog/bin/Debug/netstandard2.0/Fable.Logging.Structlog.dll
  Fable.Logging.Test -> /home/dbrattli/developer/Fable.Logging/test/bin/Debug/net10.0/Fable.Logging.Test.dll

Build succeeded.
0 Warning(s)
0 Error(s)

Time Elapsed 00:00:04.74
�[37mFable 5.13.0: F# to Beam compiler (status: alpha)
�[39m�[22m�[37m
Thanks to the contributor! @mexx
�[39m�[22m�[37mStand with Ukraine! https://standwithukraine.com.ua/

�[39m�[22m�[37mParsing test/Fable.Logging.Test.fsproj...
�[39m�[22m�[37m Determining projects to restore...
Paket version 10.3.1+bbc45f336c7f9bac95cf1d17267ab2383d029682
The last full restore is still up to date. Nothing left to do.
Total time taken: 0 milliseconds
Paket version 10.3.1+bbc45f336c7f9bac95cf1d17267ab2383d029682
The last full restore is still up to date. Nothing left to do.
Total time taken: 0 milliseconds
Restored /home/dbrattli/developer/Fable.Logging/src/Fable.Logging/Fable.Logging.fsproj (in 128 ms).
Restored /home/dbrattli/developer/Fable.Logging/src/Fable.Logging.Structlog/Fable.Logging.Structlog.fsproj (in 128 ms).
Fable.Logging -> /home/dbrattli/developer/Fable.Logging/src/Fable.Logging/bin/Release/netstandard2.0/Fable.Logging.dll
Fable.Logging.Structlog -> /home/dbrattli/developer/Fable.Logging/src/Fable.Logging.Structlog/bin/Release/netstandard2.0/Fable.Logging.Structlog.dll

Build succeeded.
0 Warning(s)
0 Error(s)

Time Elapsed 00:00:03.10

�[39m�[22m�[37mProject and references (45 source files) parsed in 8702ms

�[39m�[22m�[37mStarted Fable compilation...
�[39m�[22m�[37m
Fable compilation finished in 1773ms

�[39m�[22m�[33m./test/TestBeamLogger.fs(18,20): (18,36) warning FSHARP: It is recommended that objects supporting the IDisposable interface are created using the syntax 'new Type(args)', rather than 'Type(args)' or 'Type' as a function value representing the constructor, to indicate that resources may be owned by the generated value (code 760)
�[39m�[22m�[33m./test/TestBeamLogger.fs(28,20): (28,36) warning FSHARP: It is recommended that objects supporting the IDisposable interface are created using the syntax 'new Type(args)', rather than 'Type(args)' or 'Type' as a function value representing the constructor, to indicate that resources may be owned by the generated value (code 760)
�[39m�[22m�[33m./test/TestBeamLogger.fs(39,20): (39,36) warning FSHARP: It is recommended that objects supporting the IDisposable interface are created using the syntax 'new Type(args)', rather than 'Type(args)' or 'Type' as a function value representing the constructor, to indicate that resources may be owned by the generated value (code 760)
�[39m�[22m�[33m./test/TestBeamLogger.fs(54,20): (54,36) warning FSHARP: It is recommended that objects supporting the IDisposable interface are created using the syntax 'new Type(args)', rather than 'Type(args)' or 'Type' as a function value representing the constructor, to indicate that resources may be owned by the generated value (code 760)
�[39m�[22m�[33m./test/TestBeamLogger.fs(65,20): (65,36) warning FSHARP: It is recommended that objects supporting the IDisposable interface are created using the syntax 'new Type(args)', rather than 'Type(args)' or 'Type' as a function value representing the constructor, to indicate that resources may be owned by the generated value (code 760)
�[39m�[22m�[33m./test/TestBeamLogger.fs(85,20): (85,36) warning FSHARP: It is recommended that objects supporting the IDisposable interface are created using the syntax 'new Type(args)', rather than 'Type(args)' or 'Type' as a function value representing the constructor, to indicate that resources may be owned by the generated value (code 760)
�[39m�[22m===> Verifying dependencies...
===> Analyzing applications...
===> Compiling fable_beam
===> Compiling fable_logging_test
src/src_fable_logging_beam_beam_logger.erl:111:154: Warning: a term is constructed, but never used
src/src_fable_logging_beam_beam_logger.erl:111:204: Warning: a term is constructed, but never used

===> Compiling fable_library_beam

Fable.Logging Tests

PASS: translateFormat with no args
PASS: translateFormat with named placeholder
PASS: translateFormat with multiple placeholders
PASS: translateFormat with category name
PASS: translateFormat empty category name
PASS: translateFormat sets category_name parameter
PASS: ConsoleLogger implements ILogger
PASS: ConsoleLogger is always enabled
test - hello
test - debug message
PASS: ConsoleLogger logs without error
test - hello World
PASS: ConsoleLogger logs with format args
PASS: LoggerFactory.Create returns factory
PASS: LoggerFactory with provider
PASS: LoggerFactory creates logger with correct name
PASS: LoggerFactory dispatches to provider
PASS: LoggerFactory dispatches to multiple providers
PASS: LoggerFactory with configure sets minimum level
PASS: LoggerFactory.Create empty constructor
PASS: LoggerFactory AddProvider affects only later loggers
PASS: LoggerFactory exposes minimum level
PASS: LoggerFactory ClearProviders
PASS: LoggerFactory Dispose clears providers
PASS: log levels have correct ordering
PASS: log level filtering with mock logger
PASS: LogState.Create defaults
PASS: LogState.Create with parameters
PASS: LogState.Create with exception
PASS: LogDebug dispatches with Debug level
PASS: LogInformation dispatches with Information level
PASS: LogWarning dispatches with Warning level
PASS: LogError dispatches with Error level
PASS: LogCritical dispatches with Critical level
PASS: Log with exception
PASS: extension methods respect IsEnabled
PASS: LogDebug with format args
PASS: Structlog ConsoleLoggerProvider creates logger
PASS: Structlog JsonLoggerProvider creates logger
PASS: Structlog logger logs info
PASS: Structlog logger logs with format args
PASS: Structlog logger respects minimum level
PASS: Structlog JsonLogger logs JSON
PASS: Beam LoggerProvider creates logger
PASS: Beam logger logs info
=INFO REPORT==== 23-Aug-2026::22:41:06.784974 ===
beam-test - hello from beam logger
=INFO REPORT==== 23-Aug-2026::22:41:06.795036 ===
beam-test - info message
=WARNING REPORT==== 23-Aug-2026::22:41:06.795068 ===
beam-test - warning message
=ERROR REPORT==== 23-Aug-2026::22:41:06.795098 ===
beam-test - error message
PASS: Beam logger logs all levels
=CRITICAL REPORT==== 23-Aug-2026::22:41:06.795168 ===
beam-test - critical message
PASS: Beam logger logs with format args
=INFO REPORT==== 23-Aug-2026::22:41:06.795212 ===
beam-test - hello World
=WARNING REPORT==== 23-Aug-2026::22:41:06.795337 ===
beam-test - passes through
PASS: Beam logger respects minimum level
=INFO REPORT==== 23-Aug-2026::22:41:06.795545 ===
cross-process - hello from a spawned process
PASS: Beam logger is usable from a spawned process
PASS: JS LoggerProvider creates logger
PASS: JS logger logs info
PASS: JS logger logs all levels
PASS: JS logger logs with format args
PASS: JS logger respects minimum level

51/51 tests passed remains blocked before transpilation by its parallel Determining projects to restore...
Paket version 10.3.1+bbc45f336c7f9bac95cf1d17267ab2383d029682
Paket version 10.3.1+bbc45f336c7f9bac95cf1d17267ab2383d029682
Paket version 10.3.1+bbc45f336c7f9bac95cf1d17267ab2383d029682
The last full restore is still up to date. Nothing left to do.
Total time taken: 0 milliseconds
The last full restore is still up to date. Nothing left to do.
Total time taken: 0 milliseconds
The last full restore is still up to date. Nothing left to do.
Total time taken: 0 milliseconds
Paket version 10.3.1+bbc45f336c7f9bac95cf1d17267ab2383d029682
The last full restore is still up to date. Nothing left to do.
Total time taken: 0 milliseconds
Restored /home/dbrattli/developer/Fable.Logging/src/Fable.Logging.Beam/Fable.Logging.Beam.fsproj (in 138 ms).
Restored /home/dbrattli/developer/Fable.Logging/src/Fable.Logging/Fable.Logging.fsproj (in 138 ms).
Restored /home/dbrattli/developer/Fable.Logging/test/Fable.Logging.Test.fsproj (in 138 ms).
1 of 4 projects are up-to-date for restore.
Fable.Logging -> /home/dbrattli/developer/Fable.Logging/src/Fable.Logging/bin/Debug/netstandard2.0/Fable.Logging.dll
Fable.Logging.Beam -> /home/dbrattli/developer/Fable.Logging/src/Fable.Logging.Beam/bin/Debug/netstandard2.0/Fable.Logging.Beam.dll
Fable.Logging.Structlog -> /home/dbrattli/developer/Fable.Logging/src/Fable.Logging.Structlog/bin/Debug/netstandard2.0/Fable.Logging.Structlog.dll
Fable.Logging.Test -> /home/dbrattli/developer/Fable.Logging/test/bin/Debug/net10.0/Fable.Logging.Test.dll

Build succeeded.
0 Warning(s)
0 Error(s)

Time Elapsed 00:00:04.64 invocation returning no compiler diagnostics; the serial build passes.