Use same ApproximateGPs version for docs and examples

docs/make.jl

@@ -1,15 +1,79 @@
+using ApproximateGPs
+using Documenter
+
 ### Process examples
 # Always rerun examples
 const EXAMPLES_OUT = joinpath(@__DIR__, "src", "examples")
 ispath(EXAMPLES_OUT) && rm(EXAMPLES_OUT; recursive=true)
 mkpath(EXAMPLES_OUT)
 
+# The following function returns a script for instantiating the package
+# environment of an example
+# It ensures that the version of the package in which module `mod` is defined
+# (here `mod` will be ApproximateGPs loaded above) is added to the environment.
+# Thus the docs and the examples will use the same version of this package.
+# There are two special cases:
+# - If the script is executed by a GH action triggered by a new tag (i.e., release)
+#   in the package repo, then this version of the package will be downloaded and installed
+#   instead of checking out the local path
+# - If the script is executed by a GH action triggered by a new commit in the `devbranch`
+#   (by default `master`) in the package repo, then this revision of the package will be
+#   downloaded and installed instead of checking out the local path
+# This ensures that in these two cases the resulting Manifest.toml files do not fix the
+# local path of any package, and hence can be used to reproduce the package environment in
+# a clean and reproducible way.
+function instantiate_script(mod; org, name=string(nameof(mod)), devbranch="master")
+    github_repo = get(ENV, "GITHUB_REPOSITORY", "")
+    github_event_name = get(ENV, "GITHUB_EVENT_NAME", "")
+
+    repo = org * "/" * name * ".jl"
+    if github_repo == repo && github_event_name == "push"
+        github_ref = get(ENV, "GITHUB_REF", "")
+        match_tag = match(r"^refs\/tags\/(.*)$", github_ref)
+        if match_tag !== nothing
+            # tagged release
+            tag_nobuild = Documenter.version_tag_strip_build(match_tag.captures[1])
+            if tag_nobuild !== nothing
+                @info "Run examples with $name version $tag_nobuild"
+                return """
+using Pkg
+Pkg.add(PackageSpec(; name="$name", version="$version"))
+Pkg.instantiate()
+"""
+            end
+        else
+            # no release tag
+            match_branch = match(r"^refs\/heads\/(.*)$", github_ref)
+            if match_branch !== nothing && string(m.captures[1]) == devbranch
+                sha = get(ENV, "GITHUB_SHA", nothing)
+                if sha !== nothing
+                    @info "Run examples with $name commit $sha"
+                    return """
+using Pkg
+Pkg.add(PackageSpec(; name="$name", rev="$sha"))
+Pkg.instantiate()
+"""
+                end
+            end
+        end
+    end
+
+    # Default: Use local path of provided module
+    pkgdir_mod = pkgdir(mod)
+    @info "Run examples with $name, local path $pkgdir_mod"
+    return """
+using Pkg
+Pkg.develop(PackageSpec(; path="$pkgdir_mod"))
+Pkg.instantiate()
+"""
+end
+
 # Install and precompile all packages
 # Workaround for https://github.com/JuliaLang/Pkg.jl/issues/2219
 examples = filter!(isdir, readdir(joinpath(@__DIR__, "..", "examples"); join=true))
-let script = "using Pkg; Pkg.activate(ARGS[1]); Pkg.instantiate()"
+let script = instantiate_script(ApproximateGPs; org="JuliaGaussianProcesses")
     for example in examples
-        if !success(`$(Base.julia_cmd()) -e $script $example`)
+        if !success(`$(Base.julia_cmd()) --project=$example -e $script`)
             error(
                 "project environment of example ",
                 basename(example),
@@ -37,9 +101,6 @@ end
 isempty(processes) || success(processes) || error("some examples were not run successfully")
 
 ### Build documentation
-using Documenter
-
-using ApproximateGPs
 
 # Doctest setup
 DocMeta.setdocmeta!(