$ guix install -n calibre
The following package would be installed:
   calibre	3.42.0	/gnu/store/0vljc59sj1w3j0sw2nqsv8xdhh3rgbh0-calibre-3.42.0

substitute: updating substitutes from 'https://ci.guix.gnu.org'... 100.0%
The following derivations would be built:
   /gnu/store/1lqb0wk748w7myq1r88z5z4r829pwz10-calibre-3.42.0.drv
   /gnu/store/cfnrhdl2waw9rkv1k9a4qdgxhfnfcl98-python2-pyqt-5.11.3.drv
   /gnu/store/cbgslm5n0v9z16ri6r1xkvpz0cgmfv7c-qtwebkit-5.212.0-alpha2.drv
   /gnu/store/3d1kk0cnh4bn3zamlkvrwp21004ijy98-profile.drv
246.0 MB would be downloaded:
   /gnu/store/y898z656v8vj19r31l44qbmr1kr4308p-gtk+-3.24.7-bin
   /gnu/store/1d2anlhmaz64fw8mirzkg6m94dznzcj9-qtlocation-5.11.3
   /gnu/store/98v9swricl8ndclyd13h17ghk3dzbylf-bison-3.0.5
   /gnu/store/g1h44v8aglm290xcx4b4jzqvq58i5crw-qtsensors-5.11.3
   /gnu/store/78i79phz1wisjjyvp340qm6qgjz8aqal-qtwebchannel-5.11.3
   /gnu/store/f9kdk547rrwnzlz9qyl9rzff0f063dmm-qtdeclarative-5.11.3
   /gnu/store/rd2z60lhzsdfhfzq1jql3nxvl7jkd78p-gst-plugins-base-1.14.4
   /gnu/store/h31izp0g3vh49ll3frr7hy1wpbbnrkw2-qtmultimedia-5.11.3
   /gnu/store/8ldgha4pms6l06v635nq25sf4pkns2z4-qtbase-5.11.3
   /gnu/store/inw59iqwpal8pz3vxlfqdn1pjahd3rdx-libvdpau-1.2
   /gnu/store/w0kcba7gfn1bz4g6jbn91ja854kxxwlr-libwebp-1.0.2
   /gnu/store/rxqxn0mxmg0v2xg5nvpaidvpj3d1kxb7-mesa-18.3.5
   /gnu/store/3n7yhbfl1gik3n64rmy1574djpc1w6m5-gperf-3.1
   /gnu/store/cs2wv3jx03zn2nddmj2r6z2i2ydsn3gg-qtwebkit-5.212.0-alpha2.tar.xz
   /gnu/store/pr0jhgr9x6msjxs9xmw7nsyk5d5swa5k-qtwebsockets-5.11.3
   /gnu/store/cy4vy7yr0qylhv6n2s9qb9746bgxivy8-qttools-5.11.3
   /gnu/store/6ccavs7z1zix4hnf3hsl937k5yvhyqm0-python2-sip-4.19.13
   /gnu/store/2nvazvi2kip0lyyahljkrabgw2c902vp-qtxmlpatterns-5.11.3
   /gnu/store/604lpnkky9bx4lvfi7mnncry5w9gcj1l-PyQt5_gpl-5.11.3.tar.xz
   /gnu/store/gm6m43s66s2gjbbjf36q8km2ipavnz6b-qtx11extras-5.11.3
   /gnu/store/nh8mpg8xhkrxqk6h700ggw33f6nirr6f-qtconnectivity-5.11.3
   /gnu/store/hcab1z5y20b7cv50rf35y1k59nhql03k-python-sip-4.19.13
   /gnu/store/ssbnp5allg3xb9gkw10yf8yshwxpvliy-qtsvg-5.11.3
   /gnu/store/0yl4y5jmvhx5d38yzfy3ya21g8pdmmim-qtserialport-5.11.3
   /gnu/store/m8v7r24hjp480swla9bkavfgb9557lr5-perl-uri-1.73
   /gnu/store/m27iasppwc9xwpmyn1f8qfasd77wwy91-python2-flake8-3.6.0
   /gnu/store/h5csygsqz21imwp2bjrgqkxvv5rl89yc-python2-markdown-3.1.1
   /gnu/store/4r04fsfcryy5h4v2h3g6lzlibafmmdjm-module-import
   /gnu/store/af5xnphd8nl3qsrvq312idvbbq1y4vs6-xset-1.2.4
   /gnu/store/2gkqlsffkkfbb6wmsxixvwbcw7cvcfpc-python2-apsw-3.20.1-r1
   /gnu/store/l150637gk65al37kf2g9aphyvwzmympr-python2-backports-functools-lru-cache-1.5
   /gnu/store/jjck1lk8hafi7zyizl0h51pbdinfqwnh-python2-configparser-3.5.0
   /gnu/store/s2hdc8hn1z9bd0g15rd81s617i9jjii0-optipng-0.7.7
   /gnu/store/6fkdj5vid61cq3qv3cm8f2ghdb60l611-python2-pygments-2.2.0
   /gnu/store/q0k4q1gqszhgrclhs976pjv1k5fm9sik-python2-pillow-5.4.1
   /gnu/store/fjhji492pgmbni2ik1wi6xwj5aakhd0j-python2-css-parser-1.0.4
   /gnu/store/5h22r7x0y5kw47passf1vhb9pcn3zczk-python2-html5-parser-0.4.5
   /gnu/store/68b18gzqshkmi2rcvf5ind6kzh52756i-xdg-utils-1.1.3
   /gnu/store/a680l8rdmzck5mkzmqchjlllid3i305j-xprop-1.2.4
   /gnu/store/xlhxvllw0m5dm60mvlq7r5kmlyl9vjp6-python2-chardet-3.0.4
   /gnu/store/wc83b7yhng8kd937y9z3nq5xlyibshiv-module-import-compiled
   /gnu/store/7rshf07lds9w5f918zxddc0i5mcqmqd2-python2-beautifulsoup4-4.7.1
   /gnu/store/68h83ycd4493n7dgz3ixsdd36myj02p1-python2-netifaces-0.10.7
   /gnu/store/4wapfrrrh6w6wggwvq83x6r0rjf7fmx4-perl-file-desktopentry-0.22
   /gnu/store/cfpxga6nsfaz5cz2gvrjgzwigxz48s46-python2-pyflakes-2.0.0
   /gnu/store/xdcn3w69fq97ima1zdhxjbmqi7499iiq-python2-html2text-2018.1.9
   /gnu/store/253i7iwhsad5v8vivl6vwjsby4wi06jb-perl-file-basedir-0.08
   /gnu/store/l4hbghsmxnnjf52s41m0ls55zdfiaakg-calibre-3.42.0.tar.xz
   /gnu/store/ybs43qgg9s2wj87l1sc1qj1q8hhwm2my-python2-lxml-4.2.5
   /gnu/store/v35hrqjby6ccq6p1zhlkrmn2a1z8vm25-perl-ipc-system-simple-1.25
   /gnu/store/1z6xns39vrjnnlgxdk0jsdp4cdgh1pbj-python2-dukpy-0.3
   /gnu/store/2znhfcblzv3w01a611m0i120nzhn22d3-python2-msgpack-0.5.6
   /gnu/store/w0ii6fb2dmyqdbdpfkh2j5jq5ksq4x0a-python2-odfpy-1.3.3
   /gnu/store/8fjlli5shdg32qjbyisq7sbsj2ryhfiq-podofo-0.9.6
   /gnu/store/dmi0z68zhx2xpaqa30v7zzvyfsah21qc-perl-file-mimeinfo-0.29
   /gnu/store/fr2xdz5b31nqjml7kwc197qpy9msnjfl-python2-cssselect-0.9.2
   /gnu/store/2q8vb5j89ybby8m8inai2y0ya21nc0l8-python2-pycodestyle-2.4.0
   /gnu/store/8iwdxvs9bh2kqhcas3nsgqri48alci3n-python2-soupsieve-1.9.1
   /gnu/store/bgs229xavkc5lb36g9fpzx1q88gypzgf-python2-psutil-5.6.2
   /gnu/store/i526q2lnh5fd0wdsqggdbxpb72191nqk-python2-regex-2019.04.14
   /gnu/store/dxir0rz1q9cmnjkbjdjq41gi0c7j1sbn-libepoxy-1.5.3
   /gnu/store/023gvzf7gqbp61jfpc0674krwv7yiyza-mariadb-10.1.38
   /gnu/store/1r6qhwlynjv9l9iarbnr78p46h8ry7ls-sqlite-with-column-metadata-3.24.0
   /gnu/store/51c8zicc208m66hj3fp24h2bkif4ppy5-libinput-minimal-1.13.0
   /gnu/store/prvw1943a01yny8rf7vy25h6dwg46nmz-postgresql-10.7
   /gnu/store/pvx5gkymzmk0r8kglkcfas4imkzkxqg3-freeglut-3.0.0
   /gnu/store/slhclazbx16ij6kyggz667sycmyy9iii-llvm-7.0.1
   /gnu/store/c6q6z0vkmavm46d8v4dx2w2a6hjxh7a6-python2-pytest-bootstrap-3.8.0
   /gnu/store/dpvnaxiz6gfc51xjsl7vmklwv4qlwbc6-python2-pbr-minimal-3.0.1
   /gnu/store/h3nrgzyvr2fr1q77indpzkbhp1p60r31-python2-scandir-1.9.0
   /gnu/store/cc6d9mzc8v9hsg347pks7idm42yigq9h-python2-nose-1.3.7
   /gnu/store/cq8ya221jlyiyzcyqbjhbx1hma6cfwr7-python2-pyyaml-3.13
   /gnu/store/19dk3glyg0dhwrwnshrmfbzlvhp274wj-python2-pytest-3.8.0
   /gnu/store/vh12lwpi6nagpm400gbcxgdgjd0swv4m-python2-coverage-4.4.1
The following profile hooks would be built:
   /gnu/store/9kg106gi916wa8ah839vvmqw48v294fw-manual-database.drv
   /gnu/store/0mfzszxn9xfmfsiy2bi2xjvyagij980n-fonts-dir.drv
   /gnu/store/0rv44avi1cdr5bxari13b8qixv8qlz7p-xdg-desktop-database.drv
   /gnu/store/1jwdjpmzw5hjb5a68824xcxs68wlcq0m-gtk-im-modules.drv
   /gnu/store/3llkhh174p5mggl099ifxld9nszj21vi-xdg-mime-database.drv
   /gnu/store/5nkiv9lpq1fa95xqan5pamzxcd5l9nnj-gtk-icon-themes.drv
   /gnu/store/kgppgxl12ad2pmyb463vwwp46ijl5xw0-info-dir.drv
   /gnu/store/qyfvvma915ab3w17lqa7hl6wl7kzzpkr-ca-certificate-bundle.drv
   /gnu/store/zqly7smp3vw1g41c48d451clj5kc286c-glib-schemas.drv