Slow generation on .NET 6

When switching from .NET 5 to .NET 6, the Generate method takes over an order of magnitude longer, even for very simple records (e.g. Foo(int Bar)).

Job	Runtime	Mean	Error	StdDev	Ratio	RatioSD
.NET 5.0	.NET 5.0	7,574.85 ns	45.050 ns	42.139 ns	1.00	0.00
.NET 6.0	.NET 6.0	367,589.88 ns	2,163.086 ns	2,023.352 ns	48.53	0.27

Bogus does not show the same performance difference as AutoBogus:

Job	Runtime	Mean	Error	StdDev	Ratio	RatioSD
.NET 5.0	.NET 5.0	82.71 ns	0.111 ns	0.104 ns	1.00	0.00
.NET 6.0	.NET 6.0	71.28 ns	0.378 ns	0.353 ns	0.86	0.00

I have created a Gist with the code used to generate this benchmark.

It sounds odd that no one has noticed it before, so perhaps I’m using it wrong?

[paoloambrosio]

Was there a particular fix you added to make it work better?

Unfortunately, I didn’t find a way to fix it 😞 I simply noticed that tests weren’t failing anymore when sharing a single generated instance, so I’m just generating it once per test class, instead of once per test as I had to do before.

Also fwiw, I ended up publishing a forked version of Autobogus given @nickdodd79’s inactivity. It was focused on updating to .NET 6 and has pretty minimal changes, but theoretically helps this by now using .NET 6 if you want to give it a try?

I can’t see the public source code on GitHub (dead links in the NuGet page). If you want to try it yourself, the gist above contains two files: the C# project and the BenchmarkDotNet test.

[paoloambrosio]

Tried the benchmark and I get similar results with both AutoBogus 2.13.1 and AutoBogusLifeSupport 2.14.0. To be honest I didn’t see anything in the code to suggest that it would behave differently in this case, but it was worth a try 😃