{ in interpolated string break ReferenceExpression parser

[scrocquesel]

I'm trying to pass a json value to an environment variable with

var hasura = builder.AddContainer("hasura", "hasura/graphql-engine", "v2.38.0")
        .WithEnvironment(context =>
        {
             context.EnvironmentVariables.Add("HASURA_GRAPHQL_JWT_SECRET", ReferenceExpression.Create(
                $$"""
                {
                    "jwk_url": "{{keycloak.GetEndpoint("http")}}/realms/myrealm/protocol/openid-connect/certs",
                    "audience": ["poc-service"],
                    "issuer": "{{keycloak.GetEndpoint("http")}}/realms/myrealm",
                    "claims_map": {
                        "x-hasura-allowed-roles": ["admin", "user"],
                        "x-hasura-default-role": { "path": "$.roles[0]" },
                        "x-hasura-user-id": { "path": "$.sub" }
                    }
                }
                """)
            );

But it fails at runtime with

 Failed to apply environment variable 'HASURA_GRAPHQL_JWT_SECRET'. A dependency may have failed to start.
System.FormatException: Input string was not in a correct format. Failure to parse near offset 1. Expected an ASCII digit.
   at System.Text.ValueStringBuilder.AppendFormatHelper(IFormatProvider provider, String format, ReadOnlySpan`1 args)
   at System.String.FormatHelper(IFormatProvider provider, String format, ReadOnlySpan`1 args)
   at System.String.Format(IFormatProvider provider, String format, Object[] args)
   at Aspire.Hosting.ApplicationModel.ExpressionResolver.EvalExpressionAsync(ReferenceExpression expr) in /_/src/Aspire.Hosting/ApplicationModel/ExpressionResolver.cs:line 98
   at Aspire.Hosting.ApplicationModel.ExpressionResolver.ResolveInternalAsync(Object value) in /_/src/Aspire.Hosting/ApplicationModel/ExpressionResolver.cs:line 172
   at Aspire.Hosting.ApplicationModel.ExpressionResolver.ResolveWithContainerSourceAsync(IValueProvider valueProvider, String containerHostName, Boolean sourceIsContainer, CancellationToken cancellationToken) in /_/src/Aspire.Hosting/ApplicationModel/ExpressionResolver.cs:line 187
   at Aspire.Hosting.ApplicationModel.ExpressionResolver.ResolveAsync(Boolean sourceIsContainer, IValueProvider valueProvider, String containerHostName, CancellationToken cancellationToken) in /_/src/Aspire.Hosting/ApplicationModel/ExpressionResolver.cs:line 195
   at Aspire.Hosting.ApplicationModel.ResourceExtensions.GetValue(String key, IValueProvider valueProvider, ILogger logger, Boolean isContainer, String containerHostName, CancellationToken cancellationToken) in /_/src/Aspire.Hosting/ApplicationModel/ResourceExtensions.cs:line 438
   at Aspire.Hosting.ApplicationModel.ResourceExtensions.ProcessEnvironmentVariableValuesAsync(IResource resource, DistributedApplicationExecutionContext executionContext, Action`4 processValue, ILogger logger, String containerHostName, CancellationToken cancellationToken) in /_/src/Aspire.Hosting/ApplicationModel/ResourceExtensions.cs:line 338

I saw a similar issue #3787 that has been fixed.
Is this another bug or something I didn't do correctly ?

[davidfowl]

Similar to #8974 follow that issue, I'll be investigating.