I went through the same procedure and error happened in 10)
the detail is below:
--2019-09-30 11:45:45-- http://ftpmirror.gnu.org/gcc/gcc-8.3.0/gcc-8.3.0.tar.xz
Resolving ftpmirror.gnu.org (ftpmirror.gnu.org)... 209.51.188.200, 2001:470:142:5::200
Connecting to ftpmirror.gnu.org (ftpmirror.gnu.org)|209.51.188.200|:80... connected.
HTTP request sent, awaiting response... 302 Moved Temporarily
Location: http://ftp.twaren.net/Unix/GNU/gnu/gcc/gcc-8.3.0/gcc-8.3.0.tar.xz [following]
--2019-09-30 11:45:46-- http://ftp.twaren.net/Unix/GNU/gnu/gcc/gcc-8.3.0/gcc-8.3.0.tar.xz
Resolving ftp.twaren.net (ftp.twaren.net)... 140.110.96.68, 2001:e10:5c00:5::9
Connecting to ftp.twaren.net (ftp.twaren.net)|140.110.96.68|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 63694700 (61M) [application/x-xz]
Saving to: ‘/build/output/build/.gcc-8.3.0.tar.xz.VlwNYG/output’/build/output/build/.gcc-8.3.0. 100%[=====================================================>] 60.74M 4.78MB/s in 12s
2019-09-30 11:45:58 (4.98 MB/s) - ‘/build/output/build/.gcc-8.3.0.tar.xz.VlwNYG/output’ saved [63694700/63694700]
ERROR: No hash found for gcc-8.3.0.tar.xz
package/pkg-generic.mk:145: recipe for target '/build/output/build/host-gcc-initial-8.3.0/.stamp_downloaded' failed
make: *** [/build/output/build/host-gcc-initial-8.3.0/.stamp_downloaded] Error 1