ROOT Version: root-5-34-00-patches
Platform: 4.18.0-193.6.3.el8_2.x86_64 (RHEL 8.2 Ootpa)
Compiler: gcc (GCC) 8.3.1 20191121 (Red Hat 8.3.1-5)

I have been asked to install ROOT v5-34 in a machine that does not have an internet connection.

My configure line is:

./configure --prefix=/software/root/5.34

But it fails to find the LZ4 library as shown below in the output of the configure command:

Checking whether to build included lz4 ... yes

Even if the library can be found in the PATH by the command which. This is a problem, because it will then try to download the package and it will fail.

So I try the following configure line:

./configure --prefix=/software/root/5.34 --disable-builtin-lz4

But the option is ignored and the output of the configure shows that it will build the builtin_lz4 (and therefore download it from internet):

Enabled support for asimage, astiff, builtin_afterimage, builtin_glew, builtin_lz4, cintex, explicitlink, fftw3, gviz, genvector, krb5, memstat, opengl, reflex, shadowpw, shared, ssl, tmva, vdt, x11, xft, xml.

I was able to bypass the behaviour for the version 6.24 using cmake with the following line:

cmake -DCMAKE_INSTALL_PREFIX=<some-path> -Dasimage=on -Dcocoa=on -Dvdt=off -Dxrootd=off -Dclad=off <path-to-source>

Again, for version 6.24, I was not able to use the --disable option, but somehow, this combination of options resulted in the bypassing of the builtin-lz4.

This issue was opened following a suggestion in the root forum where the same question was posted earlier.

Regards,
Eduardo