diff --git a/trunk/PKGBUILD b/trunk/PKGBUILD
index 097866a..f80459c 100644
--- a/trunk/PKGBUILD
+++ b/trunk/PKGBUILD
@@ -11,7 +11,7 @@ arch=('x86_64')
 url='https://github.com/ghdl/ghdl'
 license=('GPL2')
 depends=('gcc-ada')
-makedepends=('gmp' 'mpfr' 'libmpc' 'zlib' 'llvm' 'clang' 'python-setuptools')
+makedepends=('gmp' 'libisl' 'mpfr' 'libmpc' 'zlib' 'llvm' 'clang' 'python-setuptools')
 validpgpkeys=('33C235A34C46AA3FFB293709A328C3A2C3C45C06'  # Jakub Jelinek <jakub@redhat.com>
               '13975A70E63C361C73AE69EF6EEB81F8981C74C7') # richard.guenther@gmail.com
 source=("$pkgbase-$pkgver.tar.gz::$url/archive/v$pkgver.tar.gz"
@@ -20,17 +20,15 @@ source=("$pkgbase-$pkgver.tar.gz::$url/archive/v$pkgver.tar.gz"
         "$pkgbase-llvm12.patch::https://github.com/ghdl/ghdl/commit/2cfa1098070959413f5ed7c32220d9e55262e4e4.patch"
         "$pkgbase-llvm12-DILocation.patch::https://github.com/ghdl/ghdl/commit/396eb764f49666616063d4239df83b5aed961fff.patch"
         "$pkgbase-llvm13.patch::https://github.com/ghdl/ghdl/commit/e49cb7b91946bbe866e684c47ccb703a83f78dec.patch"
-        "https://ftp.gnu.org/gnu/gcc/gcc-$_gcc/gcc-$_gcc.tar.xz"{,.sig}
-        "http://isl.gforge.inria.fr/isl-$_isl.tar.bz2")
+        "https://ftp.gnu.org/gnu/gcc/gcc-$_gcc/gcc-$_gcc.tar.xz"{,.sig})
 sha512sums=('efaa277132de3caeafedace137b58fa05bfa61567f12480092b1e8f74a4438e40c85c6e21cd0c5d65fbba3d116b65265e3939a8b5df951baf74837c1eca3196f'
-            '56c9cf30ecc6c1f7a11438d52b0e096b31cdf7ac4a76c2080c5d8c9c4b7df2bf3387bc336ee06e26d461aa470fbb73203f7936cec053dd2ae8782d77a151a673'
-            '5a0a811dbe21f5caa07b9497ce9d5ac13133f9101f7433ac7e6afb56379c7d624c97aaa43043e31ca88157abc57c0d8b3f78f508ef4a9ec620c9adbcf157a47e'
-            '30b78ac4f3d9f0ecfa0a90d7200d9fe8c1d014830a24b6d11a719e10d8a086fa788b111db086743975426fc366dd9279957aca149847aec3ca36dfcd6939f699'
-            '1fbd16323643c38ee522ed6b10d767cda1ab2054b6015ba0fb168bc3a1fe569965ac8d690055e875c34cead1c20ac35904c4acdf0a4d63635c02b8fb3555f1f8'
-            'b8cd926e951784fb9f08a838d89574586f872c7d29b308797ca617ef6e8678f34c8004f6bd02cf49c35644180c1bc614221adfa68c1ab823ce491c010582410f'
+            'aeef4fd149f6b58f7b458175833161cc07137cdbde07f2b5717d61f45997b6f6be37a2a59729204a50345e18f9ac6e28b69b60f01fbe01bea14fc1b114fbd8b5'
+            '579d30687e44a02f9da5fca2096fcfd9767a4ce2b697fd96e207338a8bd6942e1173391417adcca4537951b4cbb09a8c9e91f97fc8ea181687009a86b99fb111'
+            '8cc79c26aa1d301d9ee2ea58e9237b5a4e108de484f9df2a61df82501a59668eba4e6b7a47dde0717ba3f14a7cb6b8cbbd63e1a9d053d08fdd71a488f0a30fd6'
+            '5e8c48ed15734d1cc2fb6e7be4a5480e56ba12e973a550ebf99183d44881325ca14e29a8f58367bd847a65a3a09e6b6e94d042fcfd77783e09539e5fb2ed4db0'
+            'e9d6877c08f3100df4dac1455ba9c07b843e99c071a88e14711fed0ed459badf9f1e473ef9eb5ae674caba281039aa89882475ff4cb7fc7d09372f41004b2162'
             '42ae38928bd2e8183af445da34220964eb690b675b1892bbeb7cd5bb62be499011ec9a93397dba5e2fb681afadfc6f2767d03b9035b44ba9be807187ae6dc65e'
-            'SKIP'
-            '05dfbdbbe852e2440b272808b23210374ce4ce46298eeb4c18ca8725db834b0da607338a371e3d07a78585fc7e0de182e75bf09dff11477937228bd97b7b83f7')
+            'SKIP')
 options=(!lto)
 
 prepare() {
@@ -53,8 +51,6 @@ prepare() {
 
   cd gcc-$_gcc
 
-  ln -s ../isl-$_isl isl
-
   echo $_gcc > gcc/BASE-VER
 
   # hack! - some configure tests for header files using "$CPP $CPPFLAGS"
@@ -107,7 +103,6 @@ build() {
       --enable-languages=vhdl \
       --enable-default-pie \
       --enable-default-ssp \
-      --with-isl \
       --enable-plugin \
       --enable-lto \
       --disable-bootstrap \