ffmpeg-static Build fails on Ubuntu 18.04, gcc-8 (building nasm)

$ ./build-ubuntu.sh

[...snip...]

*** Building nasm ***
gcc -c -I/home/norru/Projects/3rdParty/ffmpeg-static/target/include -L/home/norru/Projects/3rdParty/ffmpeg-static/target/lib -fwrapv -U__STRICT_ANSI__ -fno-common -Werror=attributes -W -Wall -pedantic -Wc90-c99-compat -Wno-long-long -Werror=implicit -Werror=missing-braces -Werror=return-type -Werror=trigraphs -Werror=pointer-arith -Werror=missing-prototypes -Werror=missing-declarations -Werror=comment -Werror=vla -DHAVE_CONFIG_H -I. -I. -I./include -I./include -I./x86 -I./x86 -I./asm -I./asm -I./disasm -I./disasm -I./output -I./output -o asm/nasm.o asm/nasm.c
gcc -c -I/home/norru/Projects/3rdParty/ffmpeg-static/target/include -L/home/norru/Projects/3rdParty/ffmpeg-static/target/lib -fwrapv -U__STRICT_ANSI__ -fno-common -Werror=attributes -W -Wall -pedantic -Wc90-c99-compat -Wno-long-long -Werror=implicit -Werror=missing-braces -Werror=return-type -Werror=trigraphs -Werror=pointer-arith -Werror=missing-prototypes -Werror=missing-declarations -Werror=comment -Werror=vla -DHAVE_CONFIG_H -I. -I. -I./include -I./include -I./x86 -I./x86 -I./asm -I./asm -I./disasm -I./disasm -I./output -I./output -o stdlib/snprintf.o stdlib/snprintf.c
In file included from ./include/nasm.h:44,
                 from asm/nasm.c:48:
./include/nasmlib.h:194:1: error: ‘pure’ attribute on function returning ‘void’ [-Werror=attributes]
 void pure_func seg_init(void);
 ^~~~
In file included from stdlib/snprintf.c:13:
./include/nasmlib.h:194:1: error: ‘pure’ attribute on function returning ‘void’ [-Werror=attributes]
 void pure_func seg_init(void);
 ^~~~