1these 62 derivations will be built:2 /nix/store/njhj371sv6q9b1h2lwxj49gf8yckyb6f-nodejs-slim-26.9.0.drv3 /nix/store/27gaj0wpzk3hiz46ripq8hy45wl3ig31-nodejs-26.9.0.drv4 /nix/store/74zrajw1qx0lpls6y455gwhzwr2hfknh-npm-12.0.2.drv5 /nix/store/8glnz0ddjqzfwljbw3darr1vj5ffggzl-nodejs-26-npm-12.drv6 /nix/store/gjaz6n2z4ncs5giixcvnp3563zwkzslb-nodejs-install-executables.drv7 /nix/store/862l5nwbcwl27z73w9xcdr8px0kisndc-npm-install-hook.drv8 /nix/store/7bcrxpi2m0kfc4bqwdpq0hif52d42d4d-hermes-desktop-renderer-0.17.0.drv9 /nix/store/3rb1glkapyqjda3i3jd74a0y6n58y6vl-web-0.0.0.drv10 /nix/store/w7wjni1878m34arl16085pl95b8z7icb-hermes-tui-0.0.1.drv11 /nix/store/ibbd0ak9y3nakxasmkwkph72k2sr7crb-hermes-agent-0.20.2.drv12 /nix/store/01lpfqwy1aay74jsibmxq09wd4i3a0nk-hermes-desktop-0.17.0.drv13 /nix/store/436czjnvjayzr12c4jpzk5zqz2hjj6b2-hermes-desktop.desktop.drv14 /nix/store/7kxf93wb4yspvb217g6xvmk8jhrr7795-hermes-agent-0.20.2.drv15 /nix/store/c7zg9fl962cg7qc6hxp4c9699r2mhibd-hermes-desktop.drv16 /nix/store/k1cnm4zmg32c7gxn273278fl3m6nw1f0-hermes.drv17 /nix/store/95292bdynaciyhfffmbld0ydqcv0gr98-hermes-tui.drv18 /nix/store/byfgb3j80wv4piyrdgiap6mm23ylfmw5-hermes-tui.desktop.drv19 /nix/store/l08ijm438y7rqgi8fbp1dd58gcsssmxd-omp-17.2.15.drv20 /nix/store/n4rh3vn5jzrrlc0jsf3nb2clqk134m69-llama-cpp-0.4.1.drv21 /nix/store/dvgqv2rc7in799bl7jpydc3nym14z0ba-nixos-help.drv22 /nix/store/sjklqrv0iv4qfdiy20xw1r9aacv38v27-nixos-help.drv23 /nix/store/6yg8y5k6d9gwb3vpgi4gsrmrg8rrd3ca-system-path.drv24 /nix/store/i648ysm2v07szvlvmlbinirwlwlwhfm5-dbus-1.drv25 /nix/store/2nll31c05g0634zcd9v9zqwqvjry4q0a-X-Restart-Triggers-dbus-broker.drv26 /nix/store/ksb8vc665wmm3dbdgqgwkk8rl2jlrj15-unit-dbus-broker.service.drv27 /nix/store/1qgvi91lg3kgdaiicm2yml2mq21jb5pa-user-units.drv28 /nix/store/82slybjrgyhrc6csb07w95h8s0n2cx2y-system-generators.drv29 /nix/store/9875i3lj4mdb3p2cip7flnwrmpjr6nx4-system-shutdown.drv30 /nix/store/9lk5xg75qb5jnh1lbsgx4c1s2w7h3q18-etc-spaces-installer-install.json.drv31 /nix/store/cniilfrirp1kl3p4wk55dk29z8r9k52f-udev-rules.drv32 /nix/store/2aylcl9sr49y8f2wq0r3sis1hsrayshd-unit-spaces-live-dotfiles.service.drv33 /nix/store/3zd0kp6ml20vgnv39j0ng8vzhkxs8qhk-unit-script-hermes-dashboard-spaces-start.drv34 /nix/store/7qwj04fp74yq5xgnbnjbpnng8922ljr5-unit-hermes-dashboard-spaces.service.drv35 /nix/store/9m14ffgjfmabnvs4l06cdis4ywpz01a7-unit-hermes-agent-spaces.service.drv36 /nix/store/dra8am5hxxah2is2hy6k7kf2vgw9s6il-config.yaml.drv37 /nix/store/b24y1g65ghcaa7qi5zpdz1zzbwj0nx84-unit-llama-swap.service.drv38 /nix/store/waxsfbhaa3b88xxrzvpa7w71cmxi59c3-X-Restart-Triggers-systemd-udevd.drv39 /nix/store/bd7bcs2lbvmgcai9rxbf9wgm85k7lzv1-unit-systemd-udevd.service.drv40 /nix/store/m04j06h63fy123xzps3460i7gyvvi7d5-unit-dbus-broker.service.drv41 /nix/store/jy3qwfrk5xw2145k6z4yla62shlksaph-tmpfiles.d.drv42 /nix/store/nfx54q5rpw3wkagahy50yfsm8na08pkd-X-Restart-Triggers-systemd-tmpfiles-resetup.drv43 /nix/store/nfa5k59afa1z17ffc48ccbhdxafr3s7g-unit-systemd-tmpfiles-resetup.service.drv44 /nix/store/5wi0bz6w5ixp4jpff2p1lj4rl0dn5vhw-X-Restart-Triggers-polkit.drv45 /nix/store/qlz5bbm1zn56snq1yvi1jbksn2s017sa-unit-polkit.service.drv46 /nix/store/zdbb8k926skbxyfa2rv1p6j5k8dk3y6l-unit-accounts-daemon.service.drv47 /nix/store/cpzvsghfiylikjg40hzd18r6pgz2lz0p-system-units.drv48 /nix/store/nrig3k16ca1rgdqw7l0p4528jzk4fjr8-issue.drv49 /nix/store/36bx7rzdfhwyhgg8w9rb22psyick9y82-sudoers-in.drv50 /nix/store/pgbrksk3sibh88vxnrzmyfk9rzfzq59m-sudoers.drv51 /nix/store/r7h74i812w7a8v9v2yay4biwbwqmpinc-user-generators.drv52 /nix/store/sazv6qkfwjg1v6xya8z4lz13i9rp0a2q-hwdb.bin.drv53 /nix/store/ybiwyhjviyqb07bvahpd8xw51ln2i97d-etc-os-release.drv54 /nix/store/w31b2zb0cv2i2fny7ais0wi6lmig3p0a-etc-json.drv55 /nix/store/0z83qm9jfs410g7dqrx5k2qdfknqd870-etc-dump.drv56 /nix/store/7gkjs7wk1ipb8vshginjdilxqk7n9ww1-etc-metadata.erofs.drv57 /nix/store/hy7ak8423i4nwl83fyhdx5bvgr4p8d6l-etc.drv58 /nix/store/i7w7rwcg6w4gdygnqa9hqnw2264xg13r-etc-lowerdir.drv59 /nix/store/gbd39mnbmy4gx4ipfp8qhk81ax1704g1-activate.drv60 /nix/store/l0v4r0dhi8d4hqg79imhagc0pm5gbp64-linux-6.18.52-modules-shrunk.drv61 /nix/store/rmqaqk5w4ahagzp4kxdzkfz3ry2vf0b2-initrd-linux-6.18.52.drv62 /nix/store/na7p1gphm1kvcy9nydi93mcx2k5vn4zk-boot.json.drv63 /nix/store/m5jdwylzx41lfmj9yrwmdn3nqkhp5qkb-nixos-system-live-26.11.20260917.e554fab.drv64these 11 paths will be fetched (2.8 MiB download, 62.2 MiB unpacked):65 /nix/store/v148n14qz054gc1ihi03lclw0bl3d0ql-gnome-settings-daemon-50.1-gsettings-schemas66 /nix/store/2b90w447pwmxgqxmmxag6qgpskwd2pjh-libnma-1.10.667 /nix/store/f73rs7f8jqdy6wywl62dd0wpm65xgi1i-network-manager-applet-1.36.068 /nix/store/h462pk3bfwiyzs6dga041amjqgvb6sfq-network-manager-applet-1.36.0-man69 /nix/store/80ww8vwb347f6hpxip20p9ns9qm2s2v8-networkmanager-1.58.170 /nix/store/8ddhqlzjv41zdcd1qbzxwi8s4h26byy8-networkmanager-1.58.1-doc71 /nix/store/d3xhnpn8gxxvng914s4xzq8sg527h8xf-networkmanager-1.58.1-man72 /nix/store/scg7nbdr0i7mqaciyi058chsnplaa0ls-nixos-manual-html73 /nix/store/bignf3vlzr3l78m1qldhdf9h2i1yw4ig-upower-1.91.474 /nix/store/xlg7qizklrgjyxnc3aiw0bhzmn6p6gg9-xdg-desktop-portal-1.22.175 /nix/store/4mxmvyjjjspwl1sy9jlraadp4hw5yikj-xdg-desktop-portal-gtk-1.15.376error: Cannot build '/nix/store/l08ijm438y7rqgi8fbp1dd58gcsssmxd-omp-17.2.15.drv'.77 Reason: builder failed with exit code 1.78 Output paths:79 /nix/store/4np03451gdyd4y54fwgjcyg0cah4i8x5-omp-17.2.1580 Last 25 log lines:81 > Embedding mupdf wasm...82 > Embedded mupdf wasm (10408550 bytes) into packages/coding-agent/src/utils/mupdf-wasm.wasm83 > Compiling standalone binary...84 > buildPhase completed in 12 minutes 42 seconds85 > Running phase: installPhase86 > Running phase: fixupPhase87 > shrinking RPATHs of ELF executables and libraries in /nix/store/4np03451gdyd4y54fwgjcyg0cah4i8x5-omp-17.2.1588 > shrinking /nix/store/4np03451gdyd4y54fwgjcyg0cah4i8x5-omp-17.2.15/lib/omp/pi_natives.linux-x64.node89 > shrinking /nix/store/4np03451gdyd4y54fwgjcyg0cah4i8x5-omp-17.2.15/lib/omp/omp90 > checking for references to /build/ in /nix/store/4np03451gdyd4y54fwgjcyg0cah4i8x5-omp-17.2.15...91 > patching script interpreter paths in /nix/store/4np03451gdyd4y54fwgjcyg0cah4i8x5-omp-17.2.1592 > Running phase: installCheckPhase93 >94 > [Uncaught Exception] SyntaxError: Invalid character: '\0'95 > at <parse> (/$bunfs/root/prelude-m3v6hks1.txt:1)96 > at unknown97 > at <anonymous> (/$bunfs/root/omp:458323:31)98 > at <anonymous> (/$bunfs/root/omp:52:15)99 > at <anonymous> (/$bunfs/root/omp:458333:16)100 > at <anonymous> (/$bunfs/root/omp:52:15)101 > at <anonymous> (/$bunfs/root/omp:458780:16)102 > at <anonymous> (/$bunfs/root/omp:52:15)103 > at <anonymous> (/$bunfs/root/omp:459094:16)104 > at <anonymous> (/$bunfs/root/omp:52:15)105 > at <anonymous> (/$bunfs/root/omp:615668:19)106 For full logs, run:107 nix log /nix/store/l08ijm438y7rqgi8fbp1dd58gcsssmxd-omp-17.2.15.drv108error: Cannot build '/nix/store/njhj371sv6q9b1h2lwxj49gf8yckyb6f-nodejs-slim-26.9.0.drv'.109 Reason: builder failed with exit code 2.110 Output paths:111 /nix/store/j0b8r8qyd2f6ckazg91g0khi6bqs29x7-nodejs-slim-26.9.0-npm112 /nix/store/mn8r5sjblqmigxv5lg89q4wcj5zqb16n-nodejs-slim-26.9.0113 /nix/store/q0wsxksdsll08y5qpk1qlqdfwm7d59kh-nodejs-slim-26.9.0-libv8114 /nix/store/vrlq96apygma14rqrl24ivk0xc9a91ln-nodejs-slim-26.9.0-dev115 Last 25 log lines:116 > ...117 > ok 5766 known_issues/test-stdin-is-always-net.socket118 > ---119 > duration_ms: 167.39000120 > ...121 > ok 5767 known_issues/test-stream-writable-sync-error122 > ---123 > duration_ms: 69.55300124 > ...125 > ok 5768 known_issues/test-url-parse-conformance126 > ---127 > duration_ms: 107.59200128 > ...129 > ok 5769 known_issues/test-vm-function-declaration-uses-define130 > ---131 > duration_ms: 86.44000132 > ...133 > ok 5770 known_issues/test-vm-timeout-escape-nexttick134 > ---135 > duration_ms: 806.88200136 > ...137 >138 > Failed tests:139 > out/Release/node /build/node-v26.9.0/test/parallel/test-fs-cp-async-file-modes.mjs140 > make: *** [Makefile:631: test-ci-js] Error 1141 For full logs, run:142 nix log /nix/store/njhj371sv6q9b1h2lwxj49gf8yckyb6f-nodejs-slim-26.9.0.drv143error: Cannot build '/nix/store/27gaj0wpzk3hiz46ripq8hy45wl3ig31-nodejs-26.9.0.drv'.144 Reason: 1 dependency failed.145 Output paths:146 /nix/store/n50hdwyvhvbq5pd5sbgsxzr82ahzbljz-nodejs-26.9.0147error: Cannot build '/nix/store/n4rh3vn5jzrrlc0jsf3nb2clqk134m69-llama-cpp-0.4.1.drv'.148 Reason: 1 dependency failed.149 Output paths:150 /nix/store/gpki330gi00nknnz6zv5vbpn83nl9fh6-llama-cpp-0.4.1151 /nix/store/qx2bhy3g23q4av16kjkcl97fm7dipzi7-llama-cpp-0.4.1-dev152error: Cannot build '/nix/store/74zrajw1qx0lpls6y455gwhzwr2hfknh-npm-12.0.2.drv'.153 Reason: 1 dependency failed.154 Output paths:155 /nix/store/3b4d2072n0n56l2sah4g5c1ds285s10a-npm-12.0.2156error: Cannot build '/nix/store/dra8am5hxxah2is2hy6k7kf2vgw9s6il-config.yaml.drv'.157 Reason: 1 dependency failed.158 Output paths:159 /nix/store/zxa838rkcyh2l89hsv9p11zpzdqqvlz2-config.yaml160error: Cannot build '/nix/store/8glnz0ddjqzfwljbw3darr1vj5ffggzl-nodejs-26-npm-12.drv'.161 Reason: 2 dependencies failed.162 Output paths:163 /nix/store/jhw214piflml0lsjgqhm77w38jqi4fbf-nodejs-26-npm-12164error: Cannot build '/nix/store/gjaz6n2z4ncs5giixcvnp3563zwkzslb-nodejs-install-executables.drv'.165 Reason: 1 dependency failed.166 Output paths:167 /nix/store/1mi35a0xq4bg8dx64slq5ql08l1di1m0-nodejs-install-executables168error: Cannot build '/nix/store/b24y1g65ghcaa7qi5zpdz1zzbwj0nx84-unit-llama-swap.service.drv'.169 Reason: 1 dependency failed.170 Output paths:171 /nix/store/c0gs5w2yvagjf2zgmqlh0mxif8qc6m5r-unit-llama-swap.service172error: Cannot build '/nix/store/862l5nwbcwl27z73w9xcdr8px0kisndc-npm-install-hook.drv'.173 Reason: 1 dependency failed.174 Output paths:175 /nix/store/wxf3h816cp7ixfpchy1bh2wsdplm6nmp-npm-install-hook176error: Cannot build '/nix/store/7bcrxpi2m0kfc4bqwdpq0hif52d42d4d-hermes-desktop-renderer-0.17.0.drv'.177 Reason: 2 dependencies failed.178 Output paths:179 /nix/store/zsbqq84qy7l7s7dghgwwzaw0n8iy4n3l-hermes-desktop-renderer-0.17.0180error: Cannot build '/nix/store/w7wjni1878m34arl16085pl95b8z7icb-hermes-tui-0.0.1.drv'.181 Reason: 2 dependencies failed.182 Output paths:183 /nix/store/vk7frqkr5zfgg2q9134k3gffhwvw6lp9-hermes-tui-0.0.1184error: Cannot build '/nix/store/3rb1glkapyqjda3i3jd74a0y6n58y6vl-web-0.0.0.drv'.185 Reason: 2 dependencies failed.186 Output paths:187 /nix/store/ba9j18kb0vawhdwskwh4ldwzaj8wpdwk-web-0.0.0188error: Cannot build '/nix/store/7kxf93wb4yspvb217g6xvmk8jhrr7795-hermes-agent-0.20.2.drv'.189 Reason: 3 dependencies failed.190 Output paths:191 /nix/store/adh0gbyr0qsl1zv2wkx449dpv3m6v6k9-hermes-agent-0.20.2192error: Cannot build '/nix/store/ibbd0ak9y3nakxasmkwkph72k2sr7crb-hermes-agent-0.20.2.drv'.193 Reason: 3 dependencies failed.194 Output paths:195 /nix/store/skyj7k31ic8d88109cdabhpf42wh5q0n-hermes-agent-0.20.2196error: Cannot build '/nix/store/01lpfqwy1aay74jsibmxq09wd4i3a0nk-hermes-desktop-0.17.0.drv'.197 Reason: 2 dependencies failed.198 Output paths:199 /nix/store/s9phljpc4v7mrbrgn0i3yg7zz6cdann6-hermes-desktop-0.17.0200error: Cannot build '/nix/store/9m14ffgjfmabnvs4l06cdis4ywpz01a7-unit-hermes-agent-spaces.service.drv'.201 Reason: 1 dependency failed.202 Output paths:203 /nix/store/2j10fwcdcxvac5r9vlcm66kwxlhw0qcj-unit-hermes-agent-spaces.service204error: Cannot build '/nix/store/3zd0kp6ml20vgnv39j0ng8vzhkxs8qhk-unit-script-hermes-dashboard-spaces-start.drv'.205 Reason: 1 dependency failed.206 Output paths:207 /nix/store/v6yffwwqc1gz1yfczvm60hi8ys989nvj-unit-script-hermes-dashboard-spaces-start208error: Cannot build '/nix/store/436czjnvjayzr12c4jpzk5zqz2hjj6b2-hermes-desktop.desktop.drv'.209 Reason: 1 dependency failed.210 Output paths:211 /nix/store/svvxd5fh253dkhnq91n9fyvwi145c0wh-hermes-desktop.desktop212error: Cannot build '/nix/store/c7zg9fl962cg7qc6hxp4c9699r2mhibd-hermes-desktop.drv'.213 Reason: 1 dependency failed.214 Output paths:215 /nix/store/y7xajyrd9klm902xsjz5l09nh1d9sbjn-hermes-desktop216error: Cannot build '/nix/store/7qwj04fp74yq5xgnbnjbpnng8922ljr5-unit-hermes-dashboard-spaces.service.drv'.217 Reason: 2 dependencies failed.218 Output paths:219 /nix/store/i5ngfyvc9wmq1airrq8axn9r6yy62xfc-unit-hermes-dashboard-spaces.service220error: Cannot build '/nix/store/k1cnm4zmg32c7gxn273278fl3m6nw1f0-hermes.drv'.221 Reason: 2 dependencies failed.222 Output paths:223 /nix/store/d7dgrnm94y1a4f9pml9myqcnharckgmb-hermes224error: Cannot build '/nix/store/95292bdynaciyhfffmbld0ydqcv0gr98-hermes-tui.drv'.225 Reason: 1 dependency failed.226 Output paths:227 /nix/store/wb7rqa0b4p4957jjp3g302m68y9nqy07-hermes-tui228error: Cannot build '/nix/store/byfgb3j80wv4piyrdgiap6mm23ylfmw5-hermes-tui.desktop.drv'.229 Reason: 2 dependencies failed.230 Output paths:231 /nix/store/qgz19icfsg8danx7w7cqg47i5x3y9mwc-hermes-tui.desktop232error: Cannot build '/nix/store/6yg8y5k6d9gwb3vpgi4gsrmrg8rrd3ca-system-path.drv'.233 Reason: 6 dependencies failed.234 Output paths:235 /nix/store/c4lbjnabhgxiw96760sxmxqrnagh84wd-system-path236error: Cannot build '/nix/store/5wi0bz6w5ixp4jpff2p1lj4rl0dn5vhw-X-Restart-Triggers-polkit.drv'.237 Reason: 1 dependency failed.238 Output paths:239 /nix/store/0bxzlk61b9hfvnnwry2s3bqa7fxfimcl-X-Restart-Triggers-polkit240error: Cannot build '/nix/store/i648ysm2v07szvlvmlbinirwlwlwhfm5-dbus-1.drv'.241 Reason: 1 dependency failed.242 Output paths:243 /nix/store/i6g2ljf6mw58870i30vfgr5kblfi1y2l-dbus-1244error: Cannot build '/nix/store/zdbb8k926skbxyfa2rv1p6j5k8dk3y6l-unit-accounts-daemon.service.drv'.245 Reason: 1 dependency failed.246 Output paths:247 /nix/store/nvzddw2nn39qa8p870bkgqymq7y616vs-unit-accounts-daemon.service248error: Cannot build '/nix/store/2nll31c05g0634zcd9v9zqwqvjry4q0a-X-Restart-Triggers-dbus-broker.drv'.249 Reason: 1 dependency failed.250 Output paths:251 /nix/store/w7h45xcbymlk082ab6cdd3wrcbcv4cjv-X-Restart-Triggers-dbus-broker252error: Cannot build '/nix/store/qlz5bbm1zn56snq1yvi1jbksn2s017sa-unit-polkit.service.drv'.253 Reason: 1 dependency failed.254 Output paths:255 /nix/store/6yfb38jq8q22vazgg7hb7z3vlg9xaz49-unit-polkit.service256error: Cannot build '/nix/store/ksb8vc665wmm3dbdgqgwkk8rl2jlrj15-unit-dbus-broker.service.drv'.257 Reason: 1 dependency failed.258 Output paths:259 /nix/store/cxybjznazcd894v52jd7qb2js9gvjhnx-unit-dbus-broker.service260error: Cannot build '/nix/store/m04j06h63fy123xzps3460i7gyvvi7d5-unit-dbus-broker.service.drv'.261 Reason: 1 dependency failed.262 Output paths:263 /nix/store/l6xnbnh2ylk34wm8sbv489wr80nhnnmx-unit-dbus-broker.service264error: Cannot build '/nix/store/cpzvsghfiylikjg40hzd18r6pgz2lz0p-system-units.drv'.265 Reason: 6 dependencies failed.266 Output paths:267 /nix/store/682kdrlp40jhc01dx3k9y99cm2jkxwjl-system-units268error: Cannot build '/nix/store/1qgvi91lg3kgdaiicm2yml2mq21jb5pa-user-units.drv'.269 Reason: 1 dependency failed.270 Output paths:271 /nix/store/gnnnqp8hb858rb1v5x46ipdsc4cb8fv4-user-units272error: Cannot build '/nix/store/w31b2zb0cv2i2fny7ais0wi6lmig3p0a-etc-json.drv'.273 Reason: 4 dependencies failed.274 Output paths:275 /nix/store/y55y929rqdj5qga0jhbnmxx767zvamgb-etc-json276error: Cannot build '/nix/store/hy7ak8423i4nwl83fyhdx5bvgr4p8d6l-etc.drv'.277 Reason: 4 dependencies failed.278 Output paths:279 /nix/store/40kk3s2557qy0x926lc3888c9cq8lv26-etc280error: Cannot build '/nix/store/0z83qm9jfs410g7dqrx5k2qdfknqd870-etc-dump.drv'.281 Reason: 1 dependency failed.282 Output paths:283 /nix/store/vm58x83l887dn546w1qiy7lci5yn5rjz-etc-dump284error: Cannot build '/nix/store/7gkjs7wk1ipb8vshginjdilxqk7n9ww1-etc-metadata.erofs.drv'.285 Reason: 1 dependency failed.286 Output paths:287 /nix/store/xzj8pn7m9y5cq2pbvvm2202wrvpi1bih-etc-metadata.erofs288error: Cannot build '/nix/store/gbd39mnbmy4gx4ipfp8qhk81ax1704g1-activate.drv'.289 Reason: 2 dependencies failed.290 Output paths:291 /nix/store/26lll28y4k13wkrzm4xgqb5h5w4gpgsq-activate292error: Cannot build '/nix/store/na7p1gphm1kvcy9nydi93mcx2k5vn4zk-boot.json.drv'.293 Reason: 1 dependency failed.294 Output paths:295 /nix/store/daa2jdvk7hks98qgv4g29mrv5ws56j26-boot.json296error: Cannot build '/nix/store/m5jdwylzx41lfmj9yrwmdn3nqkhp5qkb-nixos-system-live-26.11.20260917.e554fab.drv'.297 Reason: 4 dependencies failed.298 Output paths:299 /nix/store/ifgaz8zslq9884w43zvi03fj0zidf59d-nixos-system-live-26.11.20260917.e554fab