func pack errors in custom handler project because 'functions.metadata' not found

[lilyjma]

Version

4.3.0

Description

Running func pack in a custom handler errors because 'functions.metadata' not found in deployment structure. The custom handler is an mcp server, and has FWR set to dotnet-isolated. Running dotnet publish as suggested doesn't help -

local.settings.json found in root directory (/Users/lily/Desktop/Functions/mcp/functions-hosting/test/mcp-sdk-functions-hosting-dotnet).
Resolving worker runtime to 'dotnet-isolated'.
local.settings.json found in root directory (/Users/lily/Desktop/Functions/mcp/functions-hosting/test/mcp-sdk-functions-hosting-dotnet).
Resolving worker runtime to 'dotnet-isolated'.
 
Validating project...
 
  Validate host.json: PASSED
 
Building .NET project...
  Determining projects to restore...
  All projects are up-to-date for restore.
  QuickstartWeatherServer -> /Users/lily/Desktop/Functions/mcp/functions-hosting/test/mcp-sdk-functions-hosting-dotnet/bin/Release/net8.0/QuickstartWeatherServer.dll
  QuickstartWeatherServer -> /Users/lily/Desktop/Functions/mcp/functions-hosting/test/mcp-sdk-functions-hosting-dotnet/output/
 
 
Validating published output...
  Validate Published Structure: FAILED
    Required file 'functions.metadata' not found in deployment structure. Ensure 'dotnet publish' has been run.
Published output validation failed: Required file 'functions.metadata' not found in deployment structure. Ensure 'dotnet publish' has been run.

FYI @im-samz

Steps to reproduce

1. Clone this repo: https://github.com/Azure-Samples/mcp-sdk-functions-hosting-dotnet
2. Run func pack in the root