I think this might also be an issue with phobos that leaks paths to the standard library into the executable.
tobias@balu:/tmp/dub-test$ nix-store -qR /nix/store/*dub2nix-0.2.6
/nix/store/ymr28y3gfbjp25cwn7nqihbciasxxgna-libunistring-0.9.10
/nix/store/nq7z9djyxaj6j7w9mgp94a6sds1jppi4-libidn2-2.3.2
/nix/store/s9qbqh7gzacs7h68b2jfmn9l6q4jwfjz-glibc-2.33-59
/nix/store/02hgizi6v46z0a1giis0q93wq6g22d77-ncurses-6.2
/nix/store/05kg55dyr06zfz4q28g603sz7q21xfc5-perl5.34.0-Test-RequiresInternet-0.05
/nix/store/pxrdzmp8ijlz2bpsxsj2ssrn3p2ybzzf-zlib-1.2.11
/nix/store/y8v9k1mjr73ns140bfzfyf3sm5avh4gc-openssl-1.1.1m
/nix/store/5f0mkdl0q9900dhm95f9fawf6q43313s-libssh2-1.10.0
/nix/store/5ndk10qnsb9hihr18k8ddladb5i96kyn-nghttp2-1.43.0-lib
/nix/store/pbfraw351mksnkp2ni9c4rkc9cpp89iv-bash-5.1-p12
/nix/store/qkr92xrcazqjsaxcr07a8li834zxrq5q-keyutils-1.6.3-lib
/nix/store/7q1fja0rfmghfj2xfplqsyw52qwj4qcj-libkrb5-1.18
/nix/store/i43cz21vzpcypgnkawrkm7m18zynliwv-brotli-1.0.9-lib
/nix/store/0ic9qsism3kjksnjvnr8yb9hbchl5yc5-curl-7.80.0
/nix/store/6l4wq77g8mj64111f66lwgizd931dg2s-perl5.34.0-IO-HTML-1.004
/nix/store/i3d23in6871kdv2q1bcml05q072vbrfl-perl5.34.0-TimeDate-2.33
/nix/store/816nc03zz1fq9vjdrx0ryx9ikmndifbg-perl5.34.0-HTTP-Date-6.05
/nix/store/kc0nrbhhxs4dhhjwz8sd43k5y7r76a0d-perl5.34.0-Encode-Locale-1.05
/nix/store/p11z3ldwjlmj8w2kvfy5vp9x1kj99j8b-perl5.34.0-URI-5.05
/nix/store/zagi7gm1201dplqqynsv11jxdnawdywf-perl5.34.0-LWP-MediaTypes-6.04
/nix/store/2025j2r6qri1qy4b2lzf9af749cakbz1-perl5.34.0-HTTP-Message-6.26
/nix/store/39ba5cbdy20ndrh7awbschhbdz9n8cka-perl5.34.0-HTTP-Daemon-6.01
/nix/store/4f5x1000fryla2pgzsf355yqdw28d3v3-perl5.34.0-Try-Tiny-0.30
/nix/store/5b40cks3m9nhkxiy4g9jsaqbp1vipc6g-attr-2.5.1
/nix/store/rf9d67pk49l2sq26qiwwp1wl727qf11f-acl-2.3.1
/nix/store/176gh50y24c0lx2bnnmsvf9wazb73php-coreutils-9.0
/nix/store/6wcdxh3h5jp9qgrccq3n71wnalca5mf5-perl-5.34.0
/nix/store/7ccycincvjj9rlk7x3mlv1sdqi3x2qzl-perl5.34.0-File-Listing-6.14
/nix/store/csidl7dwbl9qzchlzczrrxlxzsaazxfj-perl5.34.0-Net-HTTP-6.19
/nix/store/f1rq5gyzf43kd10h2wzlvizyivzd2ir7-perl5.34.0-Test-Needs-0.002006
/nix/store/g4sjg38sly59s9yns88r07a6ynyqfrj8-perl5.34.0-HTML-Tagset-3.20
/nix/store/ijsi6sjhmx9vvcyblklw6kagq7g20vk8-perl5.34.0-HTML-Parser-3.75
/nix/store/jvn1nv8p8i9dgpzcy36nqxyc5mvjb4v2-perl5.34.0-HTTP-Negotiate-6.01
/nix/store/kni8mhh8z77crjwznjcni8lxfkdvchzl-perl5.34.0-WWW-RobotRules-6.02
I think this might also be an issue with phobos that leaks paths to the standard library into the executable.