Cannot convert ‘bool’ to ‘gzFile {aka gzFile_s*}’ - c++

Question

I am new to Linux environments, and trying to install a bioinformatics package (vcftools - https://vcftools.github.io/examples.html). For some reason I can compile without a problem in a Cygwin environment, other colleagues have installed the package without a glitch, but i get an error (per below) if I try to compile in an Ubuntu environment in a VirtualBox on the same computer. I get the following error. Does anyone have a suggestion on how to resolve this error?
$make install
output
Installing VCF tools
make[1]: Entering directory '/home/wde/selt/selectionTools/vcftools_0.1.11/cpp'
g++ -c -O2 -D_FILE_OFFSET_BITS=64 vcftools.cpp -o vcftools.o
g++ -MM -O2 -D_FILE_OFFSET_BITS=64 vcftools.cpp > vcftools.d
g++ -c -O2 -D_FILE_OFFSET_BITS=64 bcf_file.cpp -o bcf_file.o
g++ -MM -O2 -D_FILE_OFFSET_BITS=64 bcf_file.cpp > bcf_file.d
g++ -c -O2 -D_FILE_OFFSET_BITS=64 vcf_file.cpp -o vcf_file.o
vcf_file.cpp: In constructor ‘vcf_file::vcf_file()’:
**vcf_file.cpp:25:13: **error: cannot convert ‘bool’** to ‘gzFile {aka gzFile_s*}’ in assignment**
gzvcf_in = false;
^~~~~
Makefile:53: recipe for target 'vcf_file.o' failed
make[1]: *** [vcf_file.o] Error 1
make[1]: Leaving directory '/home/wde/selt/selectionTools/vcftools_0.1.11/cpp'
/bin/sh: 2: cd: can't cd to perl
Makefile:24: recipe for target 'install' failed
make: *** [install] Error 2
error with make

Answer 1

Basically what the makefile does is automating the calls to the compiler.
Thus, the output from the makefile is similar to usual compile errors you get, compiling a source file from within the command line.
The important line from the error log above is:
vcf_file.cpp: In constructor ‘vcf_file::vcf_file()’:
**vcf_file.cpp:25:13: **error: cannot convert ‘bool’** to ‘gzFile {aka gzFile_s*}’ in assignment**
gzvcf_in = false;
gzvcf_in is of type pointer to gzFile_s. Assigning a bool variable to a pointer type won't compile.
Thus, the error message. Replace, inside the vcf_file.cpp, false with the pointer literal std::nullptr or the macro NULL and re-run the makefile.
Btw. I checked the vcf_file.cpp file in the github repo from vcf. They do not contain the line leading to the above error. May you have an outdated / modified version, introducing the compiler error.