Build fails on gcc-10 as: ld: CpuAes.o:/build/truecrack/src/Crypto/CpuAes.h:1233: multiple definition of `t_rc'; CpuCore.o:/build/truecrack/src/Crypto/CpuAes.h:1237: first defined here

[trofi]

gcc-10 changed the default from -fcommon to -fno-common: https://gcc.gnu.org/PR85678

As a result build fails as:

truecrack> gcc -o truecrack  Volumes.o Crc.o Endian.o Pkcs5.o CpuCore.o Crypto.o Core.o Charset.o Utils.o Main.o Rmd160.o CpuAes.o Sha1.o Sha2.o Whirlpool.o Serpent.o Twofish.o -g -I./Common/ -I./Crypto/ -I./Cuda/ -I./Main/ -I./ -I/usr/local/cuda/include/    -lm -O3
truecrack> /<<NIX>>/binutils-2.38/bin/ld: Core.o:/build/truecrack/src/Main/Core.h:49: multiple definition of `CORE_typeAttack'; CpuCore.o:/build/truecrack/src/Main/Core.h:49: first defined here
truecrack> /<<NIX>>/binutils-2.38/bin/ld: Core.o:/build/truecrack/src/Main/Core.h:41: multiple definition of `CORE_volumePath'; CpuCore.o:/build/truecrack/src/Main/Core.h:41: first defined here
truecrack> /<<NIX>>/binutils-2.38/bin/ld: Core.o:/build/truecrack/src/Main/Core.h:61: multiple definition of `CORE_hidden'; CpuCore.o:/build/truecrack/src/Main/Core.h:61: first defined here
...

[trofi]

kalilinux has an example fix at https://gitlab.com/kalilinux/packages/truecrack/-/blob/kali/master/debian/patches/fix-multiple-declarations.patch