Try #1361:

Author: bors[bot]

src/Artifacts.jl

@@ -778,7 +778,7 @@ Ensures an artifact is installed, downloading it via the download information st
 function ensure_artifact_installed(name::String, artifacts_toml::String;
                                    platform::Platform = platform_key_abi(),
                                    pkg_uuid::Union{Base.UUID,Nothing}=nothing)
-    meta = artifact_meta(name, artifacts_toml; pkg_uuid=pkg_uuid)
+    meta = artifact_meta(name, artifacts_toml; pkg_uuid=pkg_uuid, platform=platform)
     if meta === nothing
         error("Cannot locate artifact '$(name)' in '$(artifacts_toml)'")
     end

src/versions.jl

@@ -262,7 +262,12 @@ subset of the pool of available versions, this function computes a `VersionSpec`
 includes all versions in `subset` and none of the versions in its complement.
 """
 function compress_versions(pool::Vector{VersionNumber}, subset::Vector{VersionNumber})
-    subset = sort(subset) # must copy, we mutate this
+    # Explicitly drop prerelease/build numbers, as those can confuse this.
+    # TODO: Rewrite all this to use VersionNumbers instead of VersionBounds
+    drop_build_prerelease(v::VersionNumber) = VersionNumber(v.major, v.minor, v.patch)
+    pool = drop_build_prerelease.(pool)
+    subset = sort!(drop_build_prerelease.(subset))
+
     complement = sort!(setdiff(pool, subset))
     ranges = VersionRange[]
     @label again

test/artifacts.jl

@@ -272,6 +272,8 @@ end
         bind_artifact!(artifacts_toml, "foo_txt", hash; download_info=download_info, platform=Windows(:i686))
         @test artifact_hash("foo_txt", artifacts_toml; platform=Linux(:x86_64)) == hash2
         @test artifact_hash("foo_txt", artifacts_toml; platform=Windows(:i686)) == hash
+        @test ensure_artifact_installed("foo_txt", artifacts_toml; platform=Linux(:x86_64)) == artifact_path(hash2)
+        @test ensure_artifact_installed("foo_txt", artifacts_toml; platform=Windows(:i686)) == artifact_path(hash)
 
         # Next, check that we can get the download_info properly:
         meta = artifact_meta("foo_txt", artifacts_toml; platform=Windows(:i686))

test/pkg.jl

@@ -95,6 +95,32 @@ import Pkg.Types: semver_spec, VersionSpec
     @test !(Pkg.Types.isjoinable(Pkg.Types.VersionBound((1,5)), Pkg.Types.VersionBound((1,6,0))))
 end
 
+@testset "compress_versions()" begin
+    # Test exact version matching
+    vs = [v"1.1.0", v"1.1.1", v"1.1.2"]
+    @test Pkg.Types.compress_versions(vs, [vs[2]]) == Pkg.Types.VersionSpec("1.1.1")
+    
+    # Test holes
+    vs = [v"1.1.0", v"1.1.1", v"1.1.4"]
+    @test Pkg.Types.compress_versions(vs, [vs[2]]) == Pkg.Types.VersionSpec("1.1.1")
+    
+    # Test patch variation with length(subset) > 1
+    vs = [v"1.1.0", v"1.1.1", v"1.1.2", v"1.1.3", v"1.2.0"]
+    @test Pkg.Types.compress_versions(vs, [vs[2], vs[3]]) == Pkg.Types.VersionSpec("1.1.1-1.1.2")
+    
+    # Test minor variation
+    vs = [v"1.1.0", v"1.1.1", v"1.2.0"]
+    @test Pkg.Types.compress_versions(vs, [vs[2]]) == Pkg.Types.VersionSpec("1.1.1-1.1")
+   
+    # Test major variation
+    vs = [v"1.1.0", v"1.1.1", v"1.2.0", v"2.0.0"]
+    @test Pkg.Types.compress_versions(vs, [vs[2], vs[3]]) == Pkg.Types.VersionSpec("1.1.1-1")
+
+    # Test build numbers and prerelease values are ignored
+    vs = [v"1.1.0-alpha", v"1.1.0+0", v"1.1.0+1"]
+    @test Pkg.Types.compress_versions(vs, [vs[2]]) == Pkg.Types.VersionSpec("1")
+end
+
 # TODO: Should rewrite these tests not to rely on internals like field names
 @testset "union, isjoinable" begin
     @test sprint(print, VersionRange("0-0.3.2")) == "0-0.3.2"