diff --git a/Project.toml b/Project.toml
index 8e2cb92e2..98459eb0b 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,6 +1,6 @@
 name = "DynamicPPL"
 uuid = "366bfd00-2699-11ea-058f-f148b4cae6d8"
-version = "0.28.5"
+version = "0.28.6"
 
 [deps]
 ADTypes = "47edcb42-4c32-4615-8424-f2b9edc5f35b"
diff --git a/src/simple_varinfo.jl b/src/simple_varinfo.jl
index a6b907701..f4c84a5c3 100644
--- a/src/simple_varinfo.jl
+++ b/src/simple_varinfo.jl
@@ -429,22 +429,17 @@ function subset(varinfo::SimpleVarInfo, vns::AbstractVector{<:VarName})
     return Accessors.@set varinfo.values = _subset(varinfo.values, vns)
 end
 
-function _subset(x::AbstractDict, vns)
+function _subset(x::AbstractDict, vns::AbstractVector{VN}) where {VN<:VarName}
     vns_present = collect(keys(x))
-    vns_found = mapreduce(vcat, vns) do vn
+    vns_found = mapreduce(vcat, vns; init=VN[]) do vn
         return filter(Base.Fix1(subsumes, vn), vns_present)
     end
-
-    # NOTE: This `vns` to be subsume varnames explicitly present in `x`.
+    C = ConstructionBase.constructorof(typeof(x))
     if isempty(vns_found)
-        throw(
-            ArgumentError(
-                "Cannot subset `AbstractDict` with `VarName` which does not subsume any keys.",
-            ),
-        )
+        return C()
+    else
+        return C(vn => x[vn] for vn in vns_found)
     end
-    C = ConstructionBase.constructorof(typeof(x))
-    return C(vn => x[vn] for vn in vns_found)
 end
 
 function _subset(x::NamedTuple, vns)
diff --git a/src/varinfo.jl b/src/varinfo.jl
index 903789325..6278d260f 100644
--- a/src/varinfo.jl
+++ b/src/varinfo.jl
@@ -264,20 +264,24 @@ function subset(varinfo::TypedVarInfo, vns::AbstractVector{<:VarName})
     return VarInfo(NamedTuple{syms}(metadatas), varinfo.logp, varinfo.num_produce)
 end
 
-function subset(metadata::Metadata, vns_given::AbstractVector{<:VarName})
+function subset(metadata::Metadata, vns_given::AbstractVector{VN}) where {VN<:VarName}
     # TODO: Should we error if `vns` contains a variable that is not in `metadata`?
     # For each `vn` in `vns`, get the variables subsumed by `vn`.
-    vns = mapreduce(vcat, vns_given) do vn
+    vns = mapreduce(vcat, vns_given; init=VN[]) do vn
         filter(Base.Fix1(subsumes, vn), metadata.vns)
     end
     indices_for_vns = map(Base.Fix1(getindex, metadata.idcs), vns)
-    indices = Dict(vn => i for (i, vn) in enumerate(vns))
+    indices = if isempty(vns)
+        Dict{VarName,Int}()
+    else
+        Dict(vn => i for (i, vn) in enumerate(vns))
+    end
     # Construct new `vals` and `ranges`.
     vals_original = metadata.vals
     ranges_original = metadata.ranges
     # Allocate the new `vals`. and `ranges`.
-    vals = similar(metadata.vals, sum(length, ranges_original[indices_for_vns]))
-    ranges = similar(ranges_original)
+    vals = similar(metadata.vals, sum(length, ranges_original[indices_for_vns]; init=0))
+    ranges = similar(ranges_original, length(vns))
     # The new range `r` for `vns[i]` is offset by `offset` and
     # has the same length as the original range `r_original`.
     # The new `indices` (from above) ensures ordering according to `vns`.
@@ -311,7 +315,7 @@ function subset(metadata::Metadata, vns_given::AbstractVector{<:VarName})
         ranges,
         vals,
         metadata.dists[indices_for_vns],
-        metadata.gids,
+        metadata.gids[indices_for_vns],
         metadata.orders[indices_for_vns],
         flags,
     )
@@ -382,7 +386,7 @@ function merge_metadata(metadata_left::Metadata, metadata_right::Metadata)
     ranges = Vector{UnitRange{Int}}()
     vals = T[]
     dists = D[]
-    gids = metadata_right.gids  # NOTE: giving precedence to `metadata_right`
+    gids = Set{Selector}[]
     orders = Int[]
     flags = Dict{String,BitVector}()
     # Initialize the `flags`.
@@ -412,6 +416,8 @@ function merge_metadata(metadata_left::Metadata, metadata_right::Metadata)
             dist_right = getdist(metadata_right, vn)
             # Give precedence to `metadata_right`.
             push!(dists, dist_right)
+            gid = metadata_right.gids[getidx(metadata_right, vn)]
+            push!(gids, gid)
             # `orders`: giving precedence to `metadata_right`
             push!(orders, getorder(metadata_right, vn))
             # `flags`
@@ -431,6 +437,8 @@ function merge_metadata(metadata_left::Metadata, metadata_right::Metadata)
             # `dists`
             dist_left = getdist(metadata_left, vn)
             push!(dists, dist_left)
+            gid = metadata_left.gids[getidx(metadata_left, vn)]
+            push!(gids, gid)
             # `orders`
             push!(orders, getorder(metadata_left, vn))
             # `flags`
@@ -449,6 +457,8 @@ function merge_metadata(metadata_left::Metadata, metadata_right::Metadata)
             # `dists`
             dist_right = getdist(metadata_right, vn)
             push!(dists, dist_right)
+            gid = metadata_right.gids[getidx(metadata_right, vn)]
+            push!(gids, gid)
             # `orders`
             push!(orders, getorder(metadata_right, vn))
             # `flags`
@@ -1594,25 +1604,40 @@ function BangBang.push!!(
     vi::VarInfo, vn::VarName, r, dist::Distribution, gidset::Set{Selector}
 )
     if vi isa UntypedVarInfo
-        @assert ~(vn in keys(vi)) "[push!!] attempt to add an exisitng variable $(getsym(vn)) ($(vn)) to VarInfo (keys=$(keys(vi))) with dist=$dist, gid=$gidset"
+        @assert ~(vn in keys(vi)) "[push!!] attempt to add an existing variable $(getsym(vn)) ($(vn)) to VarInfo (keys=$(keys(vi))) with dist=$dist, gid=$gidset"
     elseif vi isa TypedVarInfo
-        @assert ~(haskey(vi, vn)) "[push!!] attempt to add an exisitng variable $(getsym(vn)) ($(vn)) to TypedVarInfo of syms $(syms(vi)) with dist=$dist, gid=$gidset"
+        @assert ~(haskey(vi, vn)) "[push!!] attempt to add an existing variable $(getsym(vn)) ($(vn)) to TypedVarInfo of syms $(syms(vi)) with dist=$dist, gid=$gidset"
     end
 
     val = vectorize(dist, r)
-
-    meta = getmetadata(vi, vn)
-    meta.idcs[vn] = length(meta.idcs) + 1
-    push!(meta.vns, vn)
-    l = length(meta.vals)
-    n = length(val)
-    push!(meta.ranges, (l + 1):(l + n))
-    append!(meta.vals, val)
-    push!(meta.dists, dist)
-    push!(meta.gids, gidset)
-    push!(meta.orders, get_num_produce(vi))
-    push!(meta.flags["del"], false)
-    push!(meta.flags["trans"], false)
+    sym = getsym(vn)
+    if vi isa TypedVarInfo && ~haskey(vi.metadata, sym)
+        # The NamedTuple doesn't have an entry for this variable, let's add one.
+        md = Metadata(
+            Dict(vn => 1),
+            [vn],
+            [1:length(val)],
+            val,
+            [dist],
+            [gidset],
+            [get_num_produce(vi)],
+            Dict{String,BitVector}("trans" => [false], "del" => [false]),
+        )
+        vi = Accessors.@set vi.metadata[sym] = md
+    else
+        meta = getmetadata(vi, vn)
+        meta.idcs[vn] = length(meta.idcs) + 1
+        push!(meta.vns, vn)
+        l = length(meta.vals)
+        n = length(val)
+        push!(meta.ranges, (l + 1):(l + n))
+        append!(meta.vals, val)
+        push!(meta.dists, dist)
+        push!(meta.gids, gidset)
+        push!(meta.orders, get_num_produce(vi))
+        push!(meta.flags["del"], false)
+        push!(meta.flags["trans"], false)
+    end
 
     return vi
 end
diff --git a/test/varinfo.jl b/test/varinfo.jl
index 12387f6a7..ff0e7235f 100644
--- a/test/varinfo.jl
+++ b/test/varinfo.jl
@@ -145,6 +145,18 @@ DynamicPPL.getspace(::DynamicPPL.Sampler{MySAlg}) = (:s,)
         test_varinfo!(vi)
         test_varinfo!(empty!!(TypedVarInfo(vi)))
     end
+
+    @testset "push!! to TypedVarInfo" begin
+        vn_x = @varname x
+        vn_y = @varname y
+        untyped_vi = VarInfo()
+        untyped_vi = push!!(untyped_vi, vn_x, 1.0, Normal(0, 1), Selector())
+        typed_vi = TypedVarInfo(untyped_vi)
+        typed_vi = push!!(typed_vi, vn_y, 2.0, Normal(0, 1), Selector())
+        @test typed_vi[vn_x] == 1.0
+        @test typed_vi[vn_y] == 2.0
+    end
+
     @testset "setgid!" begin
         vi = VarInfo()
         meta = vi.metadata
@@ -511,6 +523,13 @@ DynamicPPL.getspace(::DynamicPPL.Sampler{MySAlg}) = (:s,)
                 else
                     vns_supported_standard
                 end
+
+            @testset ("$(convert(Vector{VarName}, vns_subset)) empty") for vns_subset in
+                                                                           vns_supported
+                varinfo_subset = subset(varinfo, VarName[])
+                @test isempty(varinfo_subset)
+            end
+
             @testset "$(convert(Vector{VarName}, vns_subset))" for vns_subset in
                                                                    vns_supported
                 varinfo_subset = subset(varinfo, vns_subset)
@@ -638,6 +657,19 @@ DynamicPPL.getspace(::DynamicPPL.Sampler{MySAlg}) = (:s,)
             @test varinfo_merged[@varname(x)] == varinfo_right[@varname(x)]
             @test DynamicPPL.getdist(varinfo_merged, @varname(x)) isa Normal
         end
+
+        # The below used to error, testing to avoid regression.
+        @testset "merge gids" begin
+            gidset_left = Set([Selector(1)])
+            vi_left = VarInfo()
+            vi_left = push!!(vi_left, @varname(x), 1.0, Normal(), gidset_left)
+            gidset_right = Set([Selector(2)])
+            vi_right = VarInfo()
+            vi_right = push!!(vi_right, @varname(y), 2.0, Normal(), gidset_right)
+            varinfo_merged = merge(vi_left, vi_right)
+            @test DynamicPPL.getgid(varinfo_merged, @varname(x)) == gidset_left
+            @test DynamicPPL.getgid(varinfo_merged, @varname(y)) == gidset_right
+        end
     end
 
     @testset "VarInfo with selectors" begin