From 4784307a7923821ba8c7f2a8941f92e08769830b Mon Sep 17 00:00:00 2001
From: Tim Holy <tim.holy@gmail.com>
Date: Sat, 9 Nov 2019 02:21:19 -0600
Subject: [PATCH] Add fallback for stale cachefiles. Fixes #371.

---
 src/pkgs.jl      | 29 ++++++++++++++++++++---------
 test/runtests.jl | 35 +++++++++++++++++++++++++++++++++++
 2 files changed, 55 insertions(+), 9 deletions(-)

diff --git a/src/pkgs.jl b/src/pkgs.jl
index 431437ba..5c5d8ebe 100644
--- a/src/pkgs.jl
+++ b/src/pkgs.jl
@@ -59,17 +59,28 @@ function pkg_fileinfo(id::PkgId)
     # Try to find the matching cache file
     paths = Base.find_all_in_cache_path(id)
     sourcepath = Base.locate_package(id)
-    for path in paths
-        Base.stale_cachefile(sourcepath, path) === true && continue
-        provides, includes_requires = parse_cache_header(path)
-        mods_files_mtimes, _ = includes_requires
-        for (pkgid, buildid) in provides
-            if pkgid.uuid === uuid && pkgid.name == name
-                return path, mods_files_mtimes
-            end
+    if length(paths) > 1
+        fpaths = filter(path->Base.stale_cachefile(sourcepath, path) !== true, paths)
+        if isempty(fpaths)
+            # Work-around for #371 (broken dependency prevents tracking):
+            # find the most recent cache file. Presumably this is the one built
+            # to load the package.
+            sort!(paths; by=path->mtime(path), rev=true)
+            deleteat!(paths, 2:length(paths))
+        else
+            paths = fpaths
+        end
+    end
+    isempty(paths) && return nothing, nothing
+    @assert length(paths) == 1
+    path = first(paths)
+    provides, includes_requires = parse_cache_header(path)
+    mods_files_mtimes, _ = includes_requires
+    for (pkgid, buildid) in provides
+        if pkgid.uuid === uuid && pkgid.name == name
+            return path, mods_files_mtimes
         end
     end
-    return nothing, nothing
 end
 
 """
diff --git a/test/runtests.jl b/test/runtests.jl
index 65a422a2..c7b6d836 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -2160,6 +2160,41 @@ end
     push!(to_remove, depot)
 end
 
+@testset "Broken dependencies (issue #371)" begin
+    testdir = newtestdir()
+    srcdir = joinpath(testdir, "DepPkg371", "src")
+    filepath = joinpath(srcdir, "DepPkg371.jl")
+    cd(testdir) do
+        Pkg.generate("DepPkg371")
+        open(filepath, "w") do io
+            println(io, """
+            module DepPkg371
+            using OrderedCollections   # undeclared dependency
+            greet() = "Hello world!"
+            end
+            """)
+        end
+    end
+    sleep(mtimedelay)
+    @info "A warning about not having OrderedCollection in dependencies is expected"
+    @eval using DepPkg371
+    @test DepPkg371.greet() == "Hello world!"
+    sleep(mtimedelay)
+    open(filepath, "w") do io
+        println(io, """
+        module DepPkg371
+        using OrderedCollections   # undeclared dependency
+        greet() = "Hello again!"
+        end
+        """)
+    end
+    yry()
+    @test DepPkg371.greet() == "Hello again!"
+
+    rm_precompile("DepPkg371")
+    pop!(LOAD_PATH)
+end
+
 @testset "entr" begin
     if !Sys.isapple()   # these tests are very flaky on OSX
         srcfile = joinpath(tempdir(), randtmp()*".jl")