diff --git a/g/GTK+/GTK+-3.24.13-GCCcore-8.3.0.eb b/g/GTK+/GTK+-3.24.13-GCCcore-8.3.0.eb
index 374a46db..a84b803b 100644
--- a/g/GTK+/GTK+-3.24.13-GCCcore-8.3.0.eb
+++ b/g/GTK+/GTK+-3.24.13-GCCcore-8.3.0.eb
@@ -20,18 +20,18 @@ builddependencies = [
     ('GObject-Introspection', '1.63.1', '-Py-3.7', True),
     ('gettext', '0.20.1', '', True),
     ('pkg-config', '0.29.2'),
-    ('cairo', '1.17.2'),
-    ('Perl', '5.30.0', '', ('GCCcore', '8.3.0')),
+    ('cairo', '1.17.2', '', True),
+    ('Perl', '5.30.0'),
 ]
 
 dependencies = [
-    ('ATK', '2.34.1'),
-    ('at-spi2-atk', '2.34.1'),
-    ('Gdk-Pixbuf', '2.38.2'),
-    ('Pango', '1.44.7'),
+    ('ATK', '2.34.1', '', True),
+    ('at-spi2-atk', '2.34.1', '', True),
+    ('Gdk-Pixbuf', '2.38.2', '', True),
+    ('Pango', '1.44.7', '', True),
     ('libepoxy', '1.5.4'),
     ('X11', '20190717'),
-    ('FriBidi', '1.0.9'),
+    ('FriBidi', '1.0.9', '', True),
 ]
 
 default_easyblock = 'ConfigureMake'
diff --git a/l/LLVM/LLVM-8.0.1-GCCcore-8.3.0.eb b/l/LLVM/LLVM-8.0.1-GCCcore-8.3.0.eb
index 47c2cbe2..465c2ffb 100644
--- a/l/LLVM/LLVM-8.0.1-GCCcore-8.3.0.eb
+++ b/l/LLVM/LLVM-8.0.1-GCCcore-8.3.0.eb
@@ -22,13 +22,13 @@ sources = ["llvm-%(version)s.src.tar.xz"]
 
 builddependencies = [
     ('CMake', '3.16.2', '', True),
-    ('Py', '2.7', '', True),
+    ('Py', '3.7', '', True),
     ('binutils', '2.32'),
 ]
 
 dependencies = [
-    ('ncurses', '6.1', '', True),
-    ('zlib', '1.2.11', '', True),
+    ('ncurses', '6.1'),
+    ('zlib', '1.2.11'),
 ]
 
 configopts = '-DBUILD_SHARED_LIBS=ON '
diff --git a/l/libepoxy/libepoxy-1.5.4-GCCcore-8.3.0.eb b/l/libepoxy/libepoxy-1.5.4-GCCcore-8.3.0.eb
index ad959c26..6f816ab9 100644
--- a/l/libepoxy/libepoxy-1.5.4-GCCcore-8.3.0.eb
+++ b/l/libepoxy/libepoxy-1.5.4-GCCcore-8.3.0.eb
@@ -18,14 +18,14 @@ sources = ['%(version)s.tar.gz']
 checksums = ['c926fcc606901f3e03e371027056fd478da43e01ce2da7ffc48b5a0de0ca107c']
 
 builddependencies = [
-    ('binutils', '2.32', '', True),
+    ('binutils', '2.32'),
     ('Meson', '0.53.0', '-Py-3.7', True),
     ('Ninja', '1.9.0', '-Py-3.7', True),
     ('pkg-config', '0.29.2', '', True),
 ]
 
 dependencies = [
-    ('X11', '20190717', '', True),
+    ('X11', '20190717'),
     ('Mesa', '19.2.1'),
 ]
 
diff --git a/l/libunwind/libunwind-1.2.1.eb b/l/libunwind/libunwind-1.2.1.eb
index 913f524a..3d9f5502 100644
--- a/l/libunwind/libunwind-1.2.1.eb
+++ b/l/libunwind/libunwind-1.2.1.eb
@@ -1,3 +1,5 @@
+# JH 2020
+
 easyblock = 'ConfigureMake'
 
 name = 'libunwind'
@@ -16,7 +18,7 @@ sources = [SOURCE_TAR_GZ]
 source_urls = [GNU_SAVANNAH_SOURCE]
 
 dependencies = [
-    ('XZ', '5.2.3', '', True),
+    ('XZ', '5.2.4', '', True),
 ]
 
 preconfigopts = 'export LIBS="$LIBS -llzma" && '
diff --git a/m/Meson/Meson-0.53.0-Py-3.7.eb b/m/Meson/Meson-0.53.0-Py-3.7.eb
index 8d5cc8d0..cdafb692 100644
--- a/m/Meson/Meson-0.53.0-Py-3.7.eb
+++ b/m/Meson/Meson-0.53.0-Py-3.7.eb
@@ -1,4 +1,4 @@
-# IT4Innovations 2019
+# JH 2020
 
 easyblock = 'PythonPackage'
 
@@ -14,7 +14,7 @@ source_urls = [PYPI_LOWER_SOURCE]
 sources = [SOURCELOWER_TAR_GZ]
 
 dependencies = [
-    ('Ninja', '1.9.0'),
+    ('Ninja', '1.9.0', '', True),
 ]
 
 download_dep_fail = True
diff --git a/o/OpenCV/OpenCV-4.2.0-Py-3.7.eb b/o/OpenCV/OpenCV-4.2.0-Py-3.7.eb
index e28af127..e9b55fdb 100644
--- a/o/OpenCV/OpenCV-4.2.0-Py-3.7.eb
+++ b/o/OpenCV/OpenCV-4.2.0-Py-3.7.eb
@@ -10,17 +10,17 @@ description = """OpenCV (Open Source Computer Vision Library) is an open source
  a common infrastructure for computer vision applications and to accelerate
  the use of machine perception in the commercial products."""
 
-toolchain = SYSTEM
+toolchain = {'name': 'intel', 'version': '2020a'} 
 
 source_urls = ['https://github.com/opencv/opencv/archive/4.2.0']
 sources = [SOURCELOWER_TAR_GZ]
 
 builddependencies = [
     ('CMake', '3.16.2', '', True),
-('slepc4py','3.12.0', '-Py-3.7'),
-('petsc4py','3.12.0', '-Py-3.7'),
-('VTK','8.2.0', '-intel-2020a-Py-3.7'),
-('numba','0.48.0', '-intel-2020a-Py-3.7'),
+('slepc4py','3.12.0', '-Py-3.7', True),
+('petsc4py','3.12.0', '-Py-3.7', True),
+('VTK','8.2.0', '-intel-2020a-Py-3.7', True),
+('numba','0.48.0', '-intel-2020a-Py-3.7', True),
 ]
 
 dependencies = [
@@ -35,7 +35,7 @@ dependencies = [
     ('Java', '13.0.1', '', True),
     ('ant', '1.10.7', '-Java-13.0.1', True),
     ('GLib', '2.64.0', '', True),
-    ('GTK+', '3.24.13', '', True),
+    ('GTK+', '3.24.13'),
 ]
 
 moduleclass = 'vis'