How to compile NuSMV 2.6.0 from source

Question

I am trying to compile the software NuSMV 2.6.0 from source.

• I clone the repo https://github.com/hklarner/NuSMV-a
• I follow instructions in README.md:

cd NuSMV-2.6.0/NuSMV/
mkdir build
cd build
cmake ..
make

but I get the following error:

[ 16%] Building C object build-cudd/util/CMakeFiles/CUDD_UTIL_LIB.dir/getopt.c.o
[ 16%] Building C object build-cudd/util/CMakeFiles/CUDD_UTIL_LIB.dir/safe_mem.c.o
[ 16%] Building C object build-cudd/util/CMakeFiles/CUDD_UTIL_LIB.dir/strsav.c.o
[ 16%] Building C object build-cudd/util/CMakeFiles/CUDD_UTIL_LIB.dir/texpand.c.o
[ 17%] Building C object build-cudd/util/CMakeFiles/CUDD_UTIL_LIB.dir/ptime.c.o
[ 17%] Building C object build-cudd/util/CMakeFiles/CUDD_UTIL_LIB.dir/prtime.c.o
[ 17%] Building C object build-cudd/util/CMakeFiles/CUDD_UTIL_LIB.dir/pipefork.c.o
NuSMV-a/NuSMV-2.6.0/cudd-2.4.1.1/util/pipefork.c: In function ‘util_pipefork’:
NuSMV-a/NuSMV-2.6.0/cudd-2.4.1.1/util/pipefork.c:46:16: error: storage size of ‘status’ isn’t known
   46 |     union wait status;
      |                ^~~~~~
NuSMV-a/NuSMV-2.6.0/cudd-2.4.1.1/util/pipefork.c:53:12: warning: implicit declaration of function ‘pipe’ [-Wimplicit-function-declaration]
   53 |     (void) pipe(topipe);
      |            ^~~~
NuSMV-a/NuSMV-2.6.0/cudd-2.4.1.1/util/pipefork.c:59:20: warning: implicit declaration of function ‘vfork’ [-Wimplicit-function-declaration]
   59 |     if ((forkpid = vfork()) == 0) {
      |                    ^~~~~
NuSMV-a/NuSMV-2.6.0/cudd-2.4.1.1/util/pipefork.c:62:9: warning: implicit declaration of function ‘dup2’ [-Wimplicit-function-declaration]
   62 |  (void) dup2(topipe[0], fileno(stdin));
      |         ^~~~
NuSMV-a/NuSMV-2.6.0/cudd-2.4.1.1/util/pipefork.c:65:9: warning: implicit declaration of function ‘close’; did you mean ‘pclose’? [-Wimplicit-function-declaration]
   65 |  (void) close(topipe[0]);
      |         ^~~~~
      |         pclose
NuSMV-a/NuSMV-2.6.0/cudd-2.4.1.1/util/pipefork.c:70:9: warning: implicit declaration of function ‘execvp’ [-Wimplicit-function-declaration]
   70 |  (void) execvp(argv[0], argv);
      |         ^~~~~~
NuSMV-a/NuSMV-2.6.0/cudd-2.4.1.1/util/pipefork.c:73:9: warning: implicit declaration of function ‘_exit’ [-Wimplicit-function-declaration]
   73 |  (void) _exit(1);
      |         ^~~~~
NuSMV-a/NuSMV-2.6.0/cudd-2.4.1.1/util/pipefork.c:73:9: warning: incompatible implicit declaration of built-in function ‘_exit’
make[2]: *** [build-cudd/util/CMakeFiles/CUDD_UTIL_LIB.dir/build.make:167: build-cudd/util/CMakeFiles/CUDD_UTIL_LIB.dir/pipefork.c.o] Error 1
make[1]: *** [CMakeFiles/Makefile2:2174: build-cudd/util/CMakeFiles/CUDD_UTIL_LIB.dir/all] Error 2

I am on Ubuntu 20.04 LTS. I have no idea what I could do to fix this. It used to work.

Can anyone help?