I would have assumed that it would check for all of the substitute urls I listed and not just the first one. Most of the packages listed below I've test built on my pine64 so they shouldn't appear in the list anymore. (ins)efraim@E5400 ~/workspace/guix-1.2.0$ time ./pre-inst-env guix weather -c 100 --system=aarch64-linux --substitute-urls="https://ci.guix.gnu.org http://pine64:3000" computing 14,359 package derivations for aarch64-linux... looking for 14,945 store items on https://ci.guix.gnu.org... updating substitutes from 'https://ci.guix.gnu.org'... 100.0% https://ci.guix.gnu.org 52.4% substitutes available (7,838 out of 14,945) at least 25,425.6 MiB of nars (compressed) 46,859.9 MiB on disk (uncompressed) 0.002 seconds per request (30.7 seconds in total) 487.1 requests per second 0.0% (3 out of 7,107) of the missing items are queued at least 1,000 queued builds aarch64-linux: 123 (12.3%) i686-linux: 401 (40.1%) x86_64-linux: 404 (40.4%) armhf-linux: 72 (7.2%) build rate: 124.61 builds per hour x86_64-linux: 50.96 builds per hour i686-linux: 35.14 builds per hour armhf-linux: 17.95 builds per hour aarch64-linux: 20.57 builds per hour updating substitutes from 'https://ci.guix.gnu.org'... 100.0% 1857 packages are missing from 'https://ci.guix.gnu.org' for 'aarch64-linux', among which: 1625 rust@1.24.1 /gnu/store/iaw29nqdhsvpg1zi4xh2i7q9v813kjyw-rust-1.24.1-cargo /gnu/store/kgn4q5nfdmh4hx32b1zd907ri0a26x26-rust-1.24.1-doc /gnu/store/fm k8vnwc1x8a91w5ybdrfbfrfiq91d3y-rust-1.24.1 766 ghc@7.10.2 /gnu/store/zcvd3yqka7s1gn323y202rqxirmldawi-ghc-7.10.2-doc /gnu/store/vhhjk5z31rgxw82bv3dmrhz2fyhvh3yl-ghc-7.10.2 749 r-yaml@2.2.1 /gnu/store/d06vsnv4rbkz389g7wrh0xbr3mb37rbk-r-yaml-2.2.1 747 r-highr@0.8 /gnu/store/gjwsyw35p4c6cd7gqrnl4xjpgys6pic7-r-highr-0.8 562 jamvm@1.5.1 /gnu/store/mwgkpyjgrw4cnvkhglz2605i7c1rpfva-jamvm-1.5.1 509 sbcl-lift@1.7.1-1.7d49a66 /gnu/store/javclx2bycs1ig5rc0z5zw86ljwc5x5m-sbcl-lift-1.7.1-1.7d49a66 488 r-rlang@0.4.8 /gnu/store/l50wdpz16295diabmp2pkkvz2q0f52p3-r-rlang-0.4.8 487 sbcl-net.didierverna.asdf-flv@2.1 /gnu/store/mk4lpkafkbpsncf7qf7i310ix9h14xal-sbcl-net.didierverna.asdf-flv-2.1 451 r-bh@1.72.0-3 /gnu/store/0n560alajilbryj94z46wabfkq6hjjm9-r-bh-1.72.0-3 436 sbcl-trivial-gray-streams@0.0.0-1.ebd59b1 /gnu/store/s4cghmgb9pf79zw9z81lnp9ff5rx6p0g-sbcl-trivial-gray-streams-0.0.0-1.ebd59b1 245 r-munsell@0.5.0 /gnu/store/2gwfqxkpjvk4yjycs26n17dxkxd2w5m0-r-munsell-0.5.0 236 r-r-cache@0.14.0 /gnu/store/2g3c41lnvir5rr5ppn3svf2acqzs2290-r-r-cache-0.14.0 236 sbcl-cffi-libffi@0.21.0 /gnu/store/znfcdhp684zvjcipi5dvydn5886xzsa4-sbcl-cffi-libffi-0.21.0 175 libpipeline@1.5.3 /gnu/store/6qi0yj1i61py5mhg02vll8b6gbjilngl-libpipeline-1.5.3 173 r-curl@4.3 /gnu/store/gv0jw7rsmjq6a6xzzil1xlml2yd59mm8-r-curl-4.3 169 python2-cffi@1.14.0 /gnu/store/d24l9z1an90d9h2dk5zhliwp5rirh6ic-python2-cffi-1.14.0 160 python2-iso8601@0.1.12 /gnu/store/ncbiv7lrikp7hqj6nykd4hsrjillg5rg-python2-iso8601-0.1.12 156 python2-pytest-cov@2.8.1 /gnu/store/xdxx4w89lqcdi9yzxrjzd2fwbq58a7dk-python2-pytest-cov-2.8.1 156 sbcl-closer-mop@1.0.0-2.19c9d33 /gnu/store/c4mch43a7w4ivhrcz0wkfb2936dyr8p3-sbcl-closer-mop-1.0.0-2.19c9d33 154 kservice@5.70.0 /gnu/store/2lhmsz7k8hgqhgahcj6bfcgmknnfbk5w-kservice-5.70.0 151 r-survival@3.2-7 /gnu/store/5yfkcacmm4lpygvfb8xk291p9f10c244-r-survival-3.2-7 148 sbcl-trivial-garbage@0.21 /gnu/store/zz75ir2q0k7gd6wprr42vxg7vsjcrb0i-sbcl-trivial-garbage-0.21 138 cl-trivial-features@0.8-1.870d03d /gnu/store/6apvh159ld0b1rwsbzav1ls90bgiq5ad-cl-trivial-features-0.8-1.870d03d 132 python2-markupsafe@1.1.1 /gnu/store/hc6aami5qjwrmdfsj0m6rky5qsz0518n-python2-markupsafe-1.1.1 128 zeromq@4.3.3 /gnu/store/kpwiaj4ng31p71p15rdww6fnggc54l8w-zeromq-4.3.3 113 webkitgtk@2.30.2 /gnu/store/2hv5x29z673nzn4m11h21xxzgb0k47hv-webkitgtk-2.30.2-doc /gnu/store/whxb77cnsbhwd0dn0dcam8hjpz0z5ffy-webkitgtk-2.30.2 110 numactl@2.0.14 /gnu/store/dlc90qk7152iqf702hkp5y1axb8fr1dj-numactl-2.0.14 106 emacs-shut-up@0.3.2 /gnu/store/g6vjsdslm4m3bp6wbz0j9rwnmp3vr1x8-emacs-shut-up-0.3.2 105 emacs-f@0.20.0 /gnu/store/ars7lf4vswnw731pklng4dprwmw41km0-emacs-f-0.20.0 real 2m43.059s user 2m10.339s sys 0m3.571s When I reversed the order of the substitute servers: (ins)efraim@E5400 ~/workspace/guix-1.2.0$ time ./pre-inst-env guix weather -c 100 --system=aarch64-linux --substitute-urls="http://pine64:3000 https://ci.guix.gnu.org" computing 14,359 package derivations for aarch64-linux... looking for 14,945 store items on http://pine64:3000... updating substitutes from 'http://pine64:3000'... 100.0% http://pine64:3000 7.7% substitutes available (1,148 out of 14,945) unknown substitute sizes 5,199.5 MiB on disk (uncompressed) 0.011 seconds per request (171.8 seconds in total) 86.0 requests per second (continuous integration information unavailable) updating substitutes from 'http://pine64:3000'... 100.0% 4885 packages are missing from 'http://pine64:3000' for 'aarch64-linux', among which: 10801 python-minimal@3.8.2 /gnu/store/r7ncfbpi0q153qybcbhpzqf5rf6wg4pg-python-minimal-3.8.2 10651 xtrans@1.4.0 /gnu/store/an00f8f7cq2hdh5pak9f50ngx4xy0bgq-xtrans-1.4.0 8954 autoconf-wrapper@2.69 /gnu/store/3m5kvv8a5196gk1x3n0qdn5f07g9v4gb-autoconf-wrapper-2.69 8470 datefudge@1.23 /gnu/store/rwk9qqb61iyn2bqy4w39j4v9llrqc6xk-datefudge-1.23 <..snip..> -- Efraim Flashner אפרים פלשנר GPG key = A28B F40C 3E55 1372 662D 14F7 41AA E7DC CA3D 8351 Confidentiality cannot be guaranteed on emails sent or received unencrypted