Fix multiple-chain method ambiguity

HISTORY.md

@@ -1,3 +1,10 @@
+# 0.40.3
+
+Fix a method ambiguity caused by a bugfix in DynamicPPL 0.37.2.
+
+This patch means that if you are using `RepeatSampler()` to sample from a model, and you want to obtain `MCMCChains.Chains` from it, you need to specify `sample(...; chain_type=MCMCChains.Chains)`.
+This only applies if the sampler itself is a `RepeatSampler`; it doesn't apply if you are using `RepeatSampler` _within_ another sampler like Gibbs.
+
 # 0.40.2
 
 `sample(model, NUTS(), N; verbose=false)` now suppresses the 'initial step size' message.

Project.toml

@@ -1,6 +1,6 @@
 name = "Turing"
 uuid = "fce5fe82-541a-59a6-adf8-730c64b5f9a0"
-version = "0.40.2"
+version = "0.40.3"
 
 [deps]
 ADTypes = "47edcb42-4c32-4615-8424-f2b9edc5f35b"

src/mcmc/abstractmcmc.jl

@@ -57,27 +57,3 @@ function AbstractMCMC.sample(
     check_model && _check_model(model, alg)
     return AbstractMCMC.sample(rng, model, Sampler(alg), ensemble, N, n_chains; kwargs...)
 end
-
-function AbstractMCMC.sample(
-    rng::AbstractRNG,
-    model::AbstractModel,
-    sampler::Union{Sampler{<:InferenceAlgorithm},RepeatSampler},
-    ensemble::AbstractMCMC.AbstractMCMCEnsemble,
-    N::Integer,
-    n_chains::Integer;
-    chain_type=MCMCChains.Chains,
-    progress=PROGRESS[],
-    kwargs...,
-)
-    return AbstractMCMC.mcmcsample(
-        rng,
-        model,
-        sampler,
-        ensemble,
-        N,
-        n_chains;
-        chain_type=chain_type,
-        progress=progress,
-        kwargs...,
-    )
-end

src/mcmc/repeat_sampler.jl

@@ -28,11 +28,6 @@ function RepeatSampler(alg::InferenceAlgorithm, num_repeat::Int)
     return RepeatSampler(Sampler(alg), num_repeat)
 end
 
-getADType(spl::RepeatSampler) = getADType(spl.sampler)
-DynamicPPL.default_chain_type(sampler::RepeatSampler) = default_chain_type(sampler.sampler)
-# TODO(mhauru) Remove the below once DynamicPPL has removed all its Selector stuff.
-DynamicPPL.inspace(vn::VarName, spl::RepeatSampler) = inspace(vn, spl.sampler)
-
 function setparams_varinfo!!(model::DynamicPPL.Model, sampler::RepeatSampler, state, params)
     return setparams_varinfo!!(model, sampler.sampler, state, params)
 end

test/Project.toml

@@ -53,7 +53,7 @@ Combinatorics = "1"
 Distributions = "0.25"
 DistributionsAD = "0.6.3"
 DynamicHMC = "2.1.6, 3.0"
-DynamicPPL = "0.37"
+DynamicPPL = "0.37.2"
 FiniteDifferences = "0.10.8, 0.11, 0.12"
 ForwardDiff = "0.10.12 - 0.10.32, 0.10, 1"
 HypothesisTests = "0.11"

test/mcmc/repeat_sampler.jl

@@ -2,6 +2,7 @@ module RepeatSamplerTests
 
 using ..Models: gdemo_default
 using DynamicPPL: Sampler
+using MCMCChains: Chains
 using StableRNGs: StableRNG
 using Test: @test, @testset
 using Turing
@@ -26,7 +27,13 @@ using Turing
         )
         repeat_sampler = RepeatSampler(sampler, num_repeats)
         chn2 = sample(
-            copy(rng), gdemo_default, repeat_sampler, MCMCThreads(), num_samples, num_chains
+            copy(rng),
+            gdemo_default,
+            repeat_sampler,
+            MCMCThreads(),
+            num_samples,
+            num_chains;
+            chain_type=Chains,
         )
         @test chn1.value == chn2.value
     end