Where system installations of 'libnng' and 'libmbedtls' development
headers are detected in the same location, it is assumed that NNG was
built with TLS support (using Mbed TLS) and TLS is configured appropriately.
Otherwise, the environment variable Sys.setenv(NANONEXT_TLS=1)
may
be set prior to installation if:
- your system installations of 'libnng' (built with TLS support) and
'libmbedtls' are in different locations; or
- you have a system installation of 'libmbedtls' but not 'libnng' and want
nanonext to download and build a more recent version of 'libnng' than
available in system repositories against this.
Note: this is not applicable to Windows systems.