diff --git a/pkgs/test/make-binary-wrapper/add-flags.c b/pkgs/test/make-binary-wrapper/add-flags/add-flags.c
similarity index 100%
rename from pkgs/test/make-binary-wrapper/add-flags.c
rename to pkgs/test/make-binary-wrapper/add-flags/add-flags.c
diff --git a/pkgs/test/make-binary-wrapper/add-flags.cmdline b/pkgs/test/make-binary-wrapper/add-flags/add-flags.cmdline
similarity index 100%
rename from pkgs/test/make-binary-wrapper/add-flags.cmdline
rename to pkgs/test/make-binary-wrapper/add-flags/add-flags.cmdline
diff --git a/pkgs/test/make-binary-wrapper/add-flags.env b/pkgs/test/make-binary-wrapper/add-flags/add-flags.env
similarity index 100%
rename from pkgs/test/make-binary-wrapper/add-flags.env
rename to pkgs/test/make-binary-wrapper/add-flags/add-flags.env
diff --git a/pkgs/test/make-binary-wrapper/argv0.c b/pkgs/test/make-binary-wrapper/argv0/argv0.c
similarity index 100%
rename from pkgs/test/make-binary-wrapper/argv0.c
rename to pkgs/test/make-binary-wrapper/argv0/argv0.c
diff --git a/pkgs/test/make-binary-wrapper/argv0.cmdline b/pkgs/test/make-binary-wrapper/argv0/argv0.cmdline
similarity index 100%
rename from pkgs/test/make-binary-wrapper/argv0.cmdline
rename to pkgs/test/make-binary-wrapper/argv0/argv0.cmdline
diff --git a/pkgs/test/make-binary-wrapper/argv0.env b/pkgs/test/make-binary-wrapper/argv0/argv0.env
similarity index 100%
rename from pkgs/test/make-binary-wrapper/argv0.env
rename to pkgs/test/make-binary-wrapper/argv0/argv0.env
diff --git a/pkgs/test/make-binary-wrapper/basic.c b/pkgs/test/make-binary-wrapper/basic/basic.c
similarity index 100%
rename from pkgs/test/make-binary-wrapper/basic.c
rename to pkgs/test/make-binary-wrapper/basic/basic.c
diff --git a/pkgs/test/make-binary-wrapper/basic.cmdline b/pkgs/test/make-binary-wrapper/basic/basic.cmdline
similarity index 100%
rename from pkgs/test/make-binary-wrapper/basic.cmdline
rename to pkgs/test/make-binary-wrapper/basic/basic.cmdline
diff --git a/pkgs/test/make-binary-wrapper/basic.env b/pkgs/test/make-binary-wrapper/basic/basic.env
similarity index 100%
rename from pkgs/test/make-binary-wrapper/basic.env
rename to pkgs/test/make-binary-wrapper/basic/basic.env
diff --git a/pkgs/test/make-binary-wrapper/chdir.c b/pkgs/test/make-binary-wrapper/chdir/chdir.c
similarity index 100%
rename from pkgs/test/make-binary-wrapper/chdir.c
rename to pkgs/test/make-binary-wrapper/chdir/chdir.c
diff --git a/pkgs/test/make-binary-wrapper/chdir.cmdline b/pkgs/test/make-binary-wrapper/chdir/chdir.cmdline
similarity index 100%
rename from pkgs/test/make-binary-wrapper/chdir.cmdline
rename to pkgs/test/make-binary-wrapper/chdir/chdir.cmdline
diff --git a/pkgs/test/make-binary-wrapper/chdir.env b/pkgs/test/make-binary-wrapper/chdir/chdir.env
similarity index 100%
rename from pkgs/test/make-binary-wrapper/chdir.env
rename to pkgs/test/make-binary-wrapper/chdir/chdir.env
diff --git a/pkgs/test/make-binary-wrapper/combination.c b/pkgs/test/make-binary-wrapper/combination/combination.c
similarity index 100%
rename from pkgs/test/make-binary-wrapper/combination.c
rename to pkgs/test/make-binary-wrapper/combination/combination.c
diff --git a/pkgs/test/make-binary-wrapper/combination.cmdline b/pkgs/test/make-binary-wrapper/combination/combination.cmdline
similarity index 100%
rename from pkgs/test/make-binary-wrapper/combination.cmdline
rename to pkgs/test/make-binary-wrapper/combination/combination.cmdline
diff --git a/pkgs/test/make-binary-wrapper/combination.env b/pkgs/test/make-binary-wrapper/combination/combination.env
similarity index 100%
rename from pkgs/test/make-binary-wrapper/combination.env
rename to pkgs/test/make-binary-wrapper/combination/combination.env
diff --git a/pkgs/test/make-binary-wrapper/default.nix b/pkgs/test/make-binary-wrapper/default.nix
index 036b70f7594e..6f086de299a0 100644
--- a/pkgs/test/make-binary-wrapper/default.nix
+++ b/pkgs/test/make-binary-wrapper/default.nix
@@ -20,16 +20,7 @@ let
     runCommand "make-binary-wrapper-test-${testname}" env ''
       mkdir -p tmp/foo # for the chdir test
 
-      source=${
-        lib.fileset.toSource {
-          root = ./.;
-          fileset = lib.fileset.unions [
-            (./. + "/${testname}.cmdline")
-            (./. + "/${testname}.c")
-            (lib.fileset.maybeMissing (./. + "/${testname}.env"))
-          ];
-        }
-      }
+      source=${./${testname}}
 
       params=$(<"$source/${testname}.cmdline")
       eval "makeCWrapper /send/me/flags $params" > wrapper.c
diff --git a/pkgs/test/make-binary-wrapper/env.c b/pkgs/test/make-binary-wrapper/env/env.c
similarity index 100%
rename from pkgs/test/make-binary-wrapper/env.c
rename to pkgs/test/make-binary-wrapper/env/env.c
diff --git a/pkgs/test/make-binary-wrapper/env.cmdline b/pkgs/test/make-binary-wrapper/env/env.cmdline
similarity index 100%
rename from pkgs/test/make-binary-wrapper/env.cmdline
rename to pkgs/test/make-binary-wrapper/env/env.cmdline
diff --git a/pkgs/test/make-binary-wrapper/env.env b/pkgs/test/make-binary-wrapper/env/env.env
similarity index 100%
rename from pkgs/test/make-binary-wrapper/env.env
rename to pkgs/test/make-binary-wrapper/env/env.env
diff --git a/pkgs/test/make-binary-wrapper/inherit-argv0.c b/pkgs/test/make-binary-wrapper/inherit-argv0/inherit-argv0.c
similarity index 100%
rename from pkgs/test/make-binary-wrapper/inherit-argv0.c
rename to pkgs/test/make-binary-wrapper/inherit-argv0/inherit-argv0.c
diff --git a/pkgs/test/make-binary-wrapper/inherit-argv0.cmdline b/pkgs/test/make-binary-wrapper/inherit-argv0/inherit-argv0.cmdline
similarity index 100%
rename from pkgs/test/make-binary-wrapper/inherit-argv0.cmdline
rename to pkgs/test/make-binary-wrapper/inherit-argv0/inherit-argv0.cmdline
diff --git a/pkgs/test/make-binary-wrapper/inherit-argv0.env b/pkgs/test/make-binary-wrapper/inherit-argv0/inherit-argv0.env
similarity index 100%
rename from pkgs/test/make-binary-wrapper/inherit-argv0.env
rename to pkgs/test/make-binary-wrapper/inherit-argv0/inherit-argv0.env
diff --git a/pkgs/test/make-binary-wrapper/invalid-env.c b/pkgs/test/make-binary-wrapper/invalid-env/invalid-env.c
similarity index 100%
rename from pkgs/test/make-binary-wrapper/invalid-env.c
rename to pkgs/test/make-binary-wrapper/invalid-env/invalid-env.c
diff --git a/pkgs/test/make-binary-wrapper/invalid-env.cmdline b/pkgs/test/make-binary-wrapper/invalid-env/invalid-env.cmdline
similarity index 100%
rename from pkgs/test/make-binary-wrapper/invalid-env.cmdline
rename to pkgs/test/make-binary-wrapper/invalid-env/invalid-env.cmdline
diff --git a/pkgs/test/make-binary-wrapper/overlength-strings.c b/pkgs/test/make-binary-wrapper/overlength-strings/overlength-strings.c
similarity index 100%
rename from pkgs/test/make-binary-wrapper/overlength-strings.c
rename to pkgs/test/make-binary-wrapper/overlength-strings/overlength-strings.c
diff --git a/pkgs/test/make-binary-wrapper/overlength-strings.cmdline b/pkgs/test/make-binary-wrapper/overlength-strings/overlength-strings.cmdline
similarity index 100%
rename from pkgs/test/make-binary-wrapper/overlength-strings.cmdline
rename to pkgs/test/make-binary-wrapper/overlength-strings/overlength-strings.cmdline
diff --git a/pkgs/test/make-binary-wrapper/overlength-strings.env b/pkgs/test/make-binary-wrapper/overlength-strings/overlength-strings.env
similarity index 100%
rename from pkgs/test/make-binary-wrapper/overlength-strings.env
rename to pkgs/test/make-binary-wrapper/overlength-strings/overlength-strings.env
diff --git a/pkgs/test/make-binary-wrapper/prefix.c b/pkgs/test/make-binary-wrapper/prefix/prefix.c
similarity index 100%
rename from pkgs/test/make-binary-wrapper/prefix.c
rename to pkgs/test/make-binary-wrapper/prefix/prefix.c
diff --git a/pkgs/test/make-binary-wrapper/prefix.cmdline b/pkgs/test/make-binary-wrapper/prefix/prefix.cmdline
similarity index 100%
rename from pkgs/test/make-binary-wrapper/prefix.cmdline
rename to pkgs/test/make-binary-wrapper/prefix/prefix.cmdline
diff --git a/pkgs/test/make-binary-wrapper/prefix.env b/pkgs/test/make-binary-wrapper/prefix/prefix.env
similarity index 100%
rename from pkgs/test/make-binary-wrapper/prefix.env
rename to pkgs/test/make-binary-wrapper/prefix/prefix.env
diff --git a/pkgs/test/make-binary-wrapper/suffix.c b/pkgs/test/make-binary-wrapper/suffix/suffix.c
similarity index 100%
rename from pkgs/test/make-binary-wrapper/suffix.c
rename to pkgs/test/make-binary-wrapper/suffix/suffix.c
diff --git a/pkgs/test/make-binary-wrapper/suffix.cmdline b/pkgs/test/make-binary-wrapper/suffix/suffix.cmdline
similarity index 100%
rename from pkgs/test/make-binary-wrapper/suffix.cmdline
rename to pkgs/test/make-binary-wrapper/suffix/suffix.cmdline
diff --git a/pkgs/test/make-binary-wrapper/suffix.env b/pkgs/test/make-binary-wrapper/suffix/suffix.env
similarity index 100%
rename from pkgs/test/make-binary-wrapper/suffix.env
rename to pkgs/test/make-binary-wrapper/suffix/suffix.env