Merge pull request #49842 from JuliaLang/sf/dont_eagerly_load_libgomp

Don't depend on `CompilerSupportLibraries_jll` from `OpenBLAS_jll`

stdlib/OpenBLAS_jll/Project.toml

@@ -3,6 +3,7 @@ uuid = "4536629a-c528-5b80-bd46-f80d51c5b363"
 version = "0.3.23+0"
 
 [deps]
+# See note in `src/OpenBLAS_jll.jl` about this dependency.
 CompilerSupportLibraries_jll = "e66e0078-7015-5450-92f7-15fbd957f2ae"
 Libdl = "8f399da3-3557-5675-b5ff-fb832c97cbdb"
 Artifacts = "56f22d72-fd6d-98f1-02f0-08ddc0907c33"

stdlib/OpenBLAS_jll/src/OpenBLAS_jll.jl

@@ -2,7 +2,17 @@
 
 ## dummy stub for https://github.com/JuliaBinaryWrappers/OpenBLAS_jll.jl
 baremodule OpenBLAS_jll
-using Base, Libdl, CompilerSupportLibraries_jll, Base.BinaryPlatforms
+using Base, Libdl, Base.BinaryPlatforms
+
+# We are explicitly NOT loading this at runtime, as it contains `libgomp`
+# which conflicts with `libiomp5`, breaking things like MKL.  In the future,
+# we hope to transition to a JLL interface that provides a more granular
+# interface than eagerly dlopen'ing all libraries provided in the JLL
+# which will eliminate issues like this, where we avoid loading a JLL
+# because we don't want to load a library that we don't even use yet.
+# using CompilerSupportLibraries_jll
+# Because of this however, we have to manually load the libraries we
+# _do_ care about, namely libgfortran
 Base.Experimental.@compiler_options compile=min optimize=0 infer=false
 
 const PATH_list = String[]
@@ -25,10 +35,13 @@ end
 
 if Sys.iswindows()
     const libopenblas = "libopenblas$(libsuffix).dll"
+    const _libgfortran = string("libgfortran-", libgfortran_version(HostPlatform()).major, ".dll")
 elseif Sys.isapple()
     const libopenblas = "@rpath/libopenblas$(libsuffix).dylib"
+    const _libgfortran = string("@rpath/", "libgfortran.", libgfortran_version(HostPlatform()).major, ".dylib")
 else
     const libopenblas = "libopenblas$(libsuffix).so"
+    const _libgfortran = string("libgfortran.so.", libgfortran_version(HostPlatform()).major)
 end
 
 function __init__()
@@ -50,6 +63,10 @@ function __init__()
         ENV["OPENBLAS_DEFAULT_NUM_THREADS"] = "1"
     end
 
+    # As mentioned above, we are sneaking this in here so that we don't have to
+    # depend on CSL_jll and load _all_ of its libraries.
+    dlopen(_libgfortran)
+
     global libopenblas_handle = dlopen(libopenblas)
     global libopenblas_path = dlpath(libopenblas_handle)
     global artifact_dir = dirname(Sys.BINDIR)

test/precompile.jl

@@ -394,7 +394,7 @@ precompile_test_harness(false) do dir
             Dict(let m = Base.root_module(Base, s)
                      Base.PkgId(m) => Base.module_build_id(m)
                  end for s in
-                [:ArgTools, :Artifacts, :Base64, :CompilerSupportLibraries_jll, :CRC32c, :Dates,
+                [:ArgTools, :Artifacts, :Base64, :CRC32c, :Dates,
                  :Downloads, :FileWatching, :Future, :InteractiveUtils, :libblastrampoline_jll,
                  :LibCURL, :LibCURL_jll, :LibGit2, :Libdl, :LinearAlgebra,
                  :Logging, :Markdown, :Mmap, :MozillaCACerts_jll, :NetworkOptions, :OpenBLAS_jll, :Pkg, :Printf,