move cache pidfile to depot while keeping specific to sourcepath

base/loading.jl

@@ -2819,10 +2819,16 @@ global mkpidlock_hook
 global trymkpidlock_hook
 global parse_pidfile_hook
 
+function cache_pidfile_path(pkg::PkgId, sourcepath::String)
+    entrypath, entryfile = cache_file_entry(pkg)
+    srcpath_hash = string(hash(sourcepath), base=16)
+    return joinpath(entrypath, srcpath_hash * ".pidfile")
+end
+
 # allows processes to wait if another process is precompiling a given source already
 function maybe_cachefile_lock(f, pkg::PkgId, srcpath::String)
     if @isdefined(mkpidlock_hook) && @isdefined(trymkpidlock_hook) && @isdefined(parse_pidfile_hook)
-        pidfile = string(srcpath, ".pidlock")
+        pidfile = cache_pidfile_path(pkg, srcpath)
         cachefile = invokelatest(trymkpidlock_hook, f, pidfile)
         if cachefile === false
             pid, hostname, age = invokelatest(parse_pidfile_hook, pidfile)