Proxy support?

[geohardtke]

Hi there!
Great project!
I tested it on my laptop and it seems to work with no issues. My main goal is to be able to use it in an HPC (I have no sudo acces and want to use nix!) . The https_proxy and HTTPS_PROXY variables are set, but seem to be ignored.

./nix-portable nix-shell --help
installing files
figuring out ssl certs
SSL_CERT_FILE not defined. trying to find certs automatically
certs seem to reside in /etc/ssl/certs. No need to set up anything
figuring out which runtime to use
bwrap executable: /flash/tmp/hardtkel/.nix-portable/bin/bwrap
nix executable: /flash/tmp/hardtkel/.nix-portable/bin/nix
proot executable: /flash/tmp/hardtkel/.nix-portable/bin/proot
testing all available runtimes...
removing cached auto selected runtime
last auto selected runtime:
testing nix --store
warning: error: unable to download 'https://cache.nixos.org/j94668amchynbl6b4wdp8900vk5mlcw9.narinfo': SSL connect error (35); retrying in 271 ms

Is there a workaround? How can I set the proxy?
Thanks!