armhf guix - many packages not in substitutes repository? How to debug

[白い熊＠相撲道 <guix-devel_gnu.org@sumou.com>]

dHi Guix: 

I'm running armhf Guix in the terminal on an Android phone. I've authorized hydra.gnu.org, ran “guix pull”, this is where the buck stops though… 

“guix package -u” never completes, fails inevitably, as it tries to build a lot of stuff locally, doesn't get everything from the substitutes repository. 

Even a simple “guix package -i ccache -n” gives me: 

~ $ guix package -i ccache -n
The following package would be installed:
   ccache	3.4.2	/gnu/store/c4r16nx7bnyf494jcj25kzis60w8sdry-ccache-3.4.2

substitute: updating list of substitutes from 'https://mirror.hydra.gnu.org'... 100.0%
The following derivations would be built:
   /gnu/store/ym5vkwj5shsdz31nkxyq23rb51y6vm01-profile.drv
   /gnu/store/zl9jh9bjkxq41xjprfshdfyq60q6hw4z-gtk-im-modules.drv
   /gnu/store/yb9f69wqiiab2v5ba196a9c63i919ix8-info-dir.drv
   /gnu/store/w2l1ibsilblq9zvd9xb92piwv46570kx-glib-schemas.drv
   /gnu/store/sp02pcl63xr481bdvawsshh0p0xjpc63-fonts-dir.drv
   /gnu/store/sk4scdsk3wd3kcdjfcs472lkwylzll5k-xdg-desktop-database.drv
   /gnu/store/5sn2gv7yixlpn1l1b9w898jma93zahi8-doxygen-1.8.14.src.tar.xz.drv
   /gnu/store/8jmcdza14xyzb69fpbdwhlfp61h4fh2g-doxygen-1.8.14.drv
   /gnu/store/4as04swmpgfa5qm8wj3yhiwj7vvjvnyw-libdrm-2.4.92.tar.xz.drv
   /gnu/store/13i7nh2m5ndralq79ymb8k8xkx62859r-libdrm-2.4.92.drv
   /gnu/store/3b0s63l4mck8m1mfjacjc8684l6blhxm-wayland-1.15.0.drv
   /gnu/store/mn5vfh1hixnvfjgqvbsz6w87wg5myn8p-json-glib-1.4.2.drv
   /gnu/store/zddxv75vv1y05drs2bac3dwgpkk17pxl-wayland-protocols-1.14.drv
   /gnu/store/b0d1fa2hdymd1aw5k5212injsk7bmx8c-module-import.drv
   /gnu/store/bf6cs1rh0zzxpssj3ks1c5jg677bzka6-gtk+-3.22.30.drv
   /gnu/store/mr1jm2wkwxl7v584bv7q13ygqb801y9z-module-import-compiled.drv
   /gnu/store/qhwf7w1bq4x8fah0srziwrs5k02vihr7-gtk-icon-themes.drv
   /gnu/store/9kfjqhp2cc09qrq2b8idfry8xg7qy6q8-xdg-mime-database.drv
   /gnu/store/3ph3lnyadhj0vfpp07kmkwh8spb16jka-ca-certificate-bundle.drv
   /gnu/store/vx5wxwmz8dpbzxr24nsqzapwdrm6aajv-manual-database.drv
94.2 MB would be downloaded:
   /gnu/store/c4r16nx7bnyf494jcj25kzis60w8sdry-ccache-3.4.2
   /gnu/store/nn7sq67ifb4kf4238kw5zyqhf3ax9jzb-texinfo-6.5
   /gnu/store/3c6wnqgr5y19fcdf7b30wf97wnz6pyl1-desktop-file-utils-0.23
   /gnu/store/j4hms5gksg9ppdhwwrsdji8hh8mxahk1-module-import
   /gnu/store/mrqx6d307kq9yf54c542r7552jvd9lmn-module-import-compiled
   /gnu/store/mawn5xaafrqxaq9b8a3shg104a4a67wj-wayland-protocols-1.14.tar.xz
   /gnu/store/pq5y1bj17pkcq6l2qq8k773byw5xmz54-module-import-compiled
   /gnu/store/qs8f1wad0nlmscn3rncb8ppcnc2f1w53-module-import
   /gnu/store/zchhihjicr2x6sq4if89cw68jx597jz2-meson-for-build-0.46.1
   /gnu/store/n44n5bpf72lw0sprd02jq9q4y0hwhyxs-module-import
   /gnu/store/xz73aqv1r54kbcgq8yhx5l6zzbjkvsbz-doxygen-1.8.14.src.tar.gz
   /gnu/store/3nmikzxa87p02fv0yisg0ik7n8w7d22v-module-import-compiled
   /gnu/store/fqnxlsqbsickk4j1j6nm0g95snnhvq5j-cmake-3.11.0
   /gnu/store/b2hrqgs2xgpk78iwvk70lvi7rxb834fl-module-import
   /gnu/store/adqqm66pmk2n4shq0brd0gpm91l84fba-bison-3.0.4
   /gnu/store/ggdn4flbvcfhpmcwjz9b8385hzbrb2dd-m4-1.4.18
   /gnu/store/l9bha748151gjyx5p9m31izmvrcnwd6g-module-import-compiled
   /gnu/store/x75c9hfs9d4nkbngq2qr88bkmx4lxdd5-bash-minimal-4.4.19
   /gnu/store/ihjv4ab6l4lp1wcx3zriqrg4dfp34bp6-flex-2.6.1
   /gnu/store/nahp7gaq0jvivcahyyp86vjpnpx5l9sv-xmlto-0.0.28
   /gnu/store/92pp5726im4sflhxk179pgzmfvlhgy47-libxslt-1.1.32
   /gnu/store/9z3pnqqh4nywxylags5k1vpica1096is-wayland-1.15.0.tar.xz
   /gnu/store/bvvdq20hzk6y9hxzmwhzxzxac7m5z7y9-docbook-xsl-1.79.1
   /gnu/store/b7ll0kaqylh6kbi1yp2a47zx12p2x1pg-docbook-xml-4.5
   /gnu/store/16cc1iyxka95wbkw335wngbyhm3wr5s8-libdrm-2.4.92.tar.bz2
   /gnu/store/c3vwlarqkq4bqfjdz52xyvsd5w88cj4n-mesa-18.1.2
   /gnu/store/f98z0xdj2zslayj0y10xknb6k96f0mhy-gtk+-3.22.30.tar.xz
   /gnu/store/dhcqjg7whrwsn7wrbkrmax6ij4c2sg05-libxkbcommon-0.8.0
   /gnu/store/92s0ckbbiyhmy6w0c4qfsbsh3yzzk5mv-xorg-server-1.19.3
   /gnu/store/d3mli5zrshf01id1zjz2sw82h1ypp66b-libepoxy-1.5.2
   /gnu/store/3qncjdd6d66hpm6rq6ax284fh431qr65-rhash-1.3.6
   /gnu/store/mgakk70yz756ajd320007dsy85iaf5xb-libuv-1.19.2
   /gnu/store/qwpzsjryhyzp1w1yp16hfr1yzi26p053-libarchive-3.3.2
   /gnu/store/rh4yy11pf4m5c6mbzh9n13bw2k1vd0hj-curl-7.59.0
   /gnu/store/i7v5na68zsxl2m9j38vcj7axvblxqvl2-xkeyboard-config-2.23.1
   /gnu/store/f98fg4q3bdvadw10p0q076qh8n2ljqkf-xkbcomp-1.4.2

This build will eventually fail, I've tried. 

Is this because after “guix pull” the package definitions are so new that many packages are not built for armhf and available on Hydra? 

Is there a way for me somehow to “update” and install packages from substitutes only? So that it would get and install the latest version built and available for the architecture? 
--
白い熊＠相撲道