[ci] do not use --root for ptests

nix/frama-c.nix

@@ -89,6 +89,8 @@ stdenv.mkDerivation rec {
   buildPhase = ''
     make config.sed
     dune build -j2 --display short @install
+    make ptests/ptests.exe
+    make ptests/wtests.exe
   '';
 
   installFlags = [

nix/main-tests.nix

@@ -32,9 +32,7 @@ stdenv.mkDerivation rec {
   '';
 
   buildPhase = ''
-    make ptests/ptests.exe
-    make ptests/wtests.exe
-    dune exec --root ptests -- frama-c-ptests tests
+    dune exec -- frama-c-ptests tests
     dune build -j1 --display short @tests/ptests
   '';
 

nix/plugins-tests.nix

@@ -40,9 +40,7 @@ stdenv.mkDerivation rec {
 
   buildPhase = ''
     export FRAMAC_WP_CACHEDIR=$wp_cache
-    make ptests/ptests.exe
-    make ptests/wtests.exe
-    dune exec --root ptests -- frama-c-ptests src/plugins/*/tests
+    dune exec -- frama-c-ptests src/plugins/*/tests
     dune build -j1 --display short @src/plugins/ptests
   '';