Fix switching tags on 1.7 and 1.6 in general

Author: vchuravy

src/toplevel_generators.jl

@@ -41,6 +41,7 @@ function generate_imports(src_name)
             using Libdl, Artifacts, JLLWrappers.Preferences, Base.BinaryPlatforms
             using Artifacts: load_artifacts_toml, unpack_platform
             using Base.BinaryPlatforms: triplet, select_platform
+            import Pkg
             if !@isdefined(augment_platform!)
                 augment_platform!(platform) = platform
             end
@@ -170,6 +171,12 @@ function generate_wrapper_load(src_name, pkg_uuid, __source__)
             end
         end
 
+        if VERSION >= v"1.6"
+            function ensure_artifact_installed(platform=host_platform)
+                Pkg.Artifacts.ensure_artifact_installed($(src_name), joinpath($(pkg_dir), "..", "Artifacts.toml"); platform=platform, pkg_uuid=$(pkg_uuid))
+            end
+        end
+
         # Load in the wrapper, if it's not `nothing`!
         if best_wrapper === nothing
             @debug(string("Unable to load ", $(src_name), "; unsupported platform ", triplet(host_platform)))

src/wrapper_generators.jl

@@ -20,6 +20,20 @@ macro generate_wrapper_header(src_name)
                 return $(artifact_expr)
             end
         end
+        function find_or_instantiate_artifact_dir()
+            @static if VERSION < v"1.6"
+                return find_artifact_dir()
+            else
+                try
+                    return find_artifact_dir()
+                catch
+                    # 1.6 does not call `.pkg/select_artifacts.jl`
+                    # 1.7+ User might switch the tag, without calling `Pkg.instantiate()`
+                    ensure_artifact_installed(host_platform)
+                    return find_artifact_dir()
+                end
+            end
+        end
     end)
 end
 
@@ -37,7 +51,7 @@ macro generate_init_header(dependencies...)
 
     return excat(
         # This either calls `@artifact_str()`, or returns a constant string if we're overridden.
-        :(global artifact_dir = find_artifact_dir()),
+        :(global artifact_dir = find_or_instantiate_artifact_dir()),
 
         # Initialize PATH_list and LIBPATH_list
         deps_path_add...,