How do two different derivations have the same roots?

nix_log.txt

shajra bagel ~  
$ nix-store -q --roots /nix/store/zr69y5131gwh9jjfpmrdbn17l30xm47v-bash42-028.drv | cat
cannot read potential root ‘/nix/var/nix/manifests’
/nix/var/nix/profiles/chroot-13-link
/nix/var/nix/profiles/default-10-link
/nix/var/nix/profiles/per-user/shajra/default-8-link

shajra bagel ~  
$ nix-store -q --roots /nix/store/yarb0fn7xgrby4a00q1r1iys2i3rl7sv-bash42-030.drv | cat
cannot read potential root ‘/nix/var/nix/manifests’
/nix/var/nix/profiles/chroot-13-link
/nix/var/nix/profiles/default-10-link
/nix/var/nix/profiles/per-user/shajra/default-8-link

shajra bagel ~  
$ nix-store -q --referrers /nix/store/zr69y5131gwh9jjfpmrdbn17l30xm47v-bash42-028.drv | cat
/nix/store/28srjfw3b64hfghsmpb52cyd1pyim2cl-bash-4.2-p47.drv
/nix/store/d6561im2l8siyrqyiv9jhahcgq0ig6m8-bash-4.2-p47.drv

shajra bagel ~  
$ nix-store -q --referrers /nix/store/yarb0fn7xgrby4a00q1r1iys2i3rl7sv-bash42-030.drv | cat
/nix/store/28srjfw3b64hfghsmpb52cyd1pyim2cl-bash-4.2-p47.drv
/nix/store/d6561im2l8siyrqyiv9jhahcgq0ig6m8-bash-4.2-p47.drv

shajra bagel ~  
$ pp-aterm -i /nix/store/28srjfw3b64hfghsmpb52cyd1pyim2cl-bash-4.2-p47.drv | cat
Derive(
  [("out", "/nix/store/mkgzispcfvqi8z65wjngkw8zdf0v15n4-bash-4.2-p47", "", "")]
, [ ("/nix/store/05h0f6i9g09splsd6b6irqfwi5vnmjiv-bash42-044.drv", ["out"])
  , ("/nix/store/0dpkx3lw0j9jfidp3bsmjkikgq6jacaf-bash42-034.drv", ["out"])
  , ("/nix/store/2ndh89aazfaxwg560rxnmfv87kz8b1mk-bash42-026.drv", ["out"])
  , ("/nix/store/2qal0hpf83bsvzwzdqvaifr394xd9g5w-bash42-047.drv", ["out"])
  , ("/nix/store/2xj4w1r63b5qbhripp7rld2v4nmsljga-bash42-003.drv", ["out"])
  , ("/nix/store/33gx1b3g5x6r2h7wybrzdc8dwhgaac0g-bash42-037.drv", ["out"])
  , ("/nix/store/3bk0k5d66n3al99ag91kwyfn984ifvjb-bash42-039.drv", ["out"])
  , ("/nix/store/3k2ls5q3hgb02crqk2xz6fva2xc29ncw-bash42-007.drv", ["out"])
  , ("/nix/store/41h254iy6g3wcw1jk4bjlrqfan43fjmj-bash42-024.drv", ["out"])
  , ("/nix/store/5ramzsvr9ci2l7ayn4hkd25rrdib6nw7-bash42-019.drv", ["out"])
  , ("/nix/store/71afggn7l8y4i8ymixvgwfyas5mlvb23-bash42-020.drv", ["out"])
  , ("/nix/store/88vxiqvzhd3x0vmhan8iw50jjbrhnjz2-bash42-032.drv", ["out"])
  , ("/nix/store/8c5glc1d8c4jjyvk1478p1rfjdlvz977-bash42-027.drv", ["out"])
  , ("/nix/store/8gi0ylmyadp6n8b6pd5572zhmwg0wjwv-bash42-006.drv", ["out"])
  , ("/nix/store/8m05xb43wym4c2llr2ybh8bmcnfkcv6n-bash42-022.drv", ["out"])
  , ("/nix/store/8wf8vj2hm8c21mq9mmy2hqh5p06gb3ms-bash42-021.drv", ["out"])
  , ("/nix/store/96sy7jfmgz924h6sm4r9kynabsinlp78-bash42-011.drv", ["out"])
  , ("/nix/store/ab199wd3j517b40zg8kvk4iy4ajifrf4-bash42-038.drv", ["out"])
  , ("/nix/store/ahzrl60m43lamb4cig1xhk7l7ambxlj6-bash42-004.drv", ["out"])
  , ("/nix/store/arqhxch449jzxc38cahy98adrsq8d9h8-bash42-041.drv", ["out"])
  , ("/nix/store/bmlnrq10v9j7285p1l60p6z9aw6n2py1-bash42-033.drv", ["out"])
  , ("/nix/store/cvzkd9z10khfwssqisqq9g9zl1hjdjaf-bash42-018.drv", ["out"])
  , ("/nix/store/d9i29vr1j2prh2acqdiwps0c51fw5k32-bash42-017.drv", ["out"])
  , ("/nix/store/f010h50296bl8qm3agh1rw4d2jc0m9s0-bash42-023.drv", ["out"])
  , ("/nix/store/f5i5ppfdirkrxgxinqmaxmz5wxpr6k7v-bash42-016.drv", ["out"])
  , ("/nix/store/fk24jiy2mx4ikdfg09w8xsivb8bivl54-bash42-042.drv", ["out"])
  , ("/nix/store/gn4rxlvprmar9v28mzv1j3l9rff1fgg2-bash-4.2.tar.gz.drv", ["out"])
  , ("/nix/store/h78va83npz006d4pi0aiw5gch6n441sm-bash42-043.drv", ["out"])
  , ("/nix/store/hk034ymyldiyp1k58gz6pcz20bz1a3dm-bash42-014.drv", ["out"])
  , ("/nix/store/ilnhd551dznazzhpv9n7wppvwgc5ybd6-bash42-010.drv", ["out"])
  , ("/nix/store/k1yjv211svfkdfdp7dbr7wm9s7wvqjyd-bash42-045.drv", ["out"])
  , ("/nix/store/k6n2rc8jf17n025y8ss7g37nb53ks4r0-stdenv-linux-boot.drv", ["out"])
  , ("/nix/store/ks4q4dpv9ncarkm0z34pnjb8sm1f9ak6-bash42-013.drv", ["out"])
  , ("/nix/store/kz4rl3qb9s13iizlfp912dcad7yki414-bash42-031.drv", ["out"])
  , ("/nix/store/l7cm00ddsdwkp3c8hn72qxk91r870w4f-bash42-015.drv", ["out"])
  , ("/nix/store/m2wqax10jjwan3cy0l0ggy9jm0vr71w7-bash42-009.drv", ["out"])
  , ("/nix/store/mx9gk33mch334szx73kfbvc9jy533q3l-bash42-036.drv", ["out"])
  , ("/nix/store/n87a4xxxafgsvjh9ab884l5rvvp5il9s-bash42-012.drv", ["out"])
  , ("/nix/store/n98hidkxfqzhdr8606ami59y6garj3dj-bash42-035.drv", ["out"])
  , ("/nix/store/nl80gn843y20d5xp0g007md5y016a8yf-bash42-008.drv", ["out"])
  , ("/nix/store/q825q17wnz9a3xp3gv5bx36x53jja2br-bootstrap-tools.drv", ["out"])
  , ("/nix/store/qhd1kr1n7p38why4y1nbzbf1ykgf23jl-bash42-002.drv", ["out"])
  , ("/nix/store/qlmmwjawvsy729ybxv0h3dmqrq12r9z7-bash42-001.drv", ["out"])
  , ("/nix/store/scga99vzjp1dwygi3wrmwnmifwymlign-bash42-025.drv", ["out"])
  , ("/nix/store/wbcgjaxdxsfddzx7xi4hgbc4c568l54w-bash42-005.drv", ["out"])
  , ("/nix/store/wpd6hr63qqlbk5v4nc65z8bnx9c71rcn-bash42-029.drv", ["out"])
  , ("/nix/store/wsabc5r1k3nrgpzhgx3rmdqy7gzgab48-bison-3.0.2.drv", ["out"])
  , ("/nix/store/x5zzrxb90k6g3kqsah20hr8iagbgm7af-bash42-040.drv", ["out"])
  , ("/nix/store/xpv93qdvkwhwp9sgggzxn7fjv2nyjcis-bash42-046.drv", ["out"])
  , ("/nix/store/yarb0fn7xgrby4a00q1r1iys2i3rl7sv-bash42-030.drv", ["out"])
  , ("/nix/store/zr69y5131gwh9jjfpmrdbn17l30xm47v-bash42-028.drv", ["out"])
  ]
, ["/nix/store/9krlzvny65gdc8s7kpb6lkx8cd02c25b-default-builder.sh"]
, "x86_64-linux"
, "/nix/store/c8lg3m5mr246fvlx6xsrxa0sykv4l9pg-bootstrap-tools/bin/sh"
, ["-e", "/nix/store/9krlzvny65gdc8s7kpb6lkx8cd02c25b-default-builder.sh"]
, [ ("NIX_CFLAGS_COMPILE", "-DSYS_BASHRC=\"/etc/bashrc\"\n-DSYS_BASH_LOGOUT=\"/etc/bash_logout\"\n-DDEFAULT_PATH_VALUE=\"/no-such-path\"\n-DSTANDARD_UTILS_PATH=\"/no-such-path\"\n-DNON_INTERACTIVE_LOGIN_SHELLS\n-DSSH_SOURCE_BASHRC\n")
  , ("buildInputs", "")
  , ("builder", "/nix/store/c8lg3m5mr246fvlx6xsrxa0sykv4l9pg-bootstrap-tools/bin/sh")
  , ("configureFlags", "--disable-readline")
  , ("enableParallelBuilding", "")
  , ("name", "bash-4.2-p47")
  , ("nativeBuildInputs", "/nix/store/j5wzxdqwyd2aj64bxam3sb5l78x8hvrv-bison-3.0.2")
  , ("out", "/nix/store/mkgzispcfvqi8z65wjngkw8zdf0v15n4-bash-4.2-p47")
  , ("patchFlags", "-p0")
  , ("patches", "/nix/store/l8nfw786mmddj2mk4q9k15qy9p34y5cx-bash42-001 /nix/store/s52zyzaskalpipdi5bm559h84lvwxk31-bash42-002 /nix/store/l9lbkvp3vakmyj5rnazz0vxy0mf28rk7-bash42-003 /nix/store/37chpv3lh48jm694j45mjc5kjlkl0jsc-bash42-004 /nix/store/z08kf5vfjpn6glf0kw4mpm92zyxzn0zc-bash42-005 /nix/store/bd2dgjbsjd21pw6zjys1brq0n78a1cyj-bash42-006 /nix/store/11b4nb4sjbrj9cgjkvgwb9vjpy5nlhr5-bash42-007 /nix/store/392mbn26anpfb2hbsk53l3jv2051fx13-bash42-008 /nix/store/7m68z1vbbcrkg8hp6q97qyr134dylx6i-bash42-009 /nix/store/wywf47yrxw1ffgsf9a59zjyc1qcyvwxh-bash42-010 /nix/store/0633p4ck7gh7vl7hkjaszb7mb1nv5q24-bash42-011 /nix/store/085gn1vsx1i9da5bgcdyzkkp5qp6wkm6-bash42-012 /nix/store/nrf7ycgy9zis5jrarprpwgvz663hm076-bash42-013 /nix/store/rs7dzg05cdy301mfj976h38718q1fdrs-bash42-014 /nix/store/ply5hnq2vgkl23mqjhr2fm86pa2270p1-bash42-015 /nix/store/zwp4iadr91lbfynn61vnzs8i1fv003gj-bash42-016 /nix/store/bl1cmw5s1mbp4003d431rm5c5177n9zy-bash42-017 /nix/store/hm62w8gd5gk39d0qjrh97zb4nsc5xxa3-bash42-018 /nix/store/jwi93vbmf6sxy826mgayc953n4x2j04w-bash42-019 /nix/store/6ss6qz1rmrv3kbrf0kcihf9b0hg4bx68-bash42-020 /nix/store/y043n8v6qz0ycavrncr7c6mlq1ncmysa-bash42-021 /nix/store/z4j9rslg0rgywbwx6swniyld4ym79dpk-bash42-022 /nix/store/5dykxnligbag8f3gnx5dn45hgkrn8hb0-bash42-023 /nix/store/v9501p4zv86sfffzagdbppwx1v60h75k-bash42-024 /nix/store/2h8mh0gcc3ggwi4azxgh3nmzn9sln45a-bash42-025 /nix/store/fd75k5g5xnxgkr3b97602s59z7y51lcx-bash42-026 /nix/store/8ql7gg2f1g3c6ba3rhxi5fdy7xkfljxp-bash42-027 /nix/store/31mbvd070afy9iq6a0k8xp66bxfmrgwm-bash42-028 /nix/store/ih64mcm3y6daqbg9cd1j7qlir45ik0z6-bash42-029 /nix/store/ln6q51m9mdnw2561bpimd4r3i75xzbqx-bash42-030 /nix/store/yqxhqskh9apxcdh0mfr3s10n8p4ldia5-bash42-031 /nix/store/c06gs6pvhxb9rnlffsh5j5hpp44933f1-bash42-032 /nix/store/a7yzy3gd7nm2jj29aqgfznjfdf0bfzb6-bash42-033 /nix/store/lnk8z1y6z6a5zpf28xjc6hjvilxlqxr3-bash42-034 /nix/store/hypc4dmkddxcpszp193w0lgz3xmam1py-bash42-035 /nix/store/34521r5546mz94nh7z3gv6cixghpwp0c-bash42-036 /nix/store/23zlg1yyg0v91nk98b9gbg47dh3sw2ws-bash42-037 /nix/store/lmry78slrvllf6273r1fzq4ks5f2gq2n-bash42-038 /nix/store/97v52xx6p5bdr9g46d7dkri74f90fh1d-bash42-039 /nix/store/q1sz5690g7kpjhhxyysm3v8fpi9gidwx-bash42-040 /nix/store/29dz5sif2c5jcl0mmx81ax4x558gvkwi-bash42-041 /nix/store/wy0pl3x834c5lgn2hn40vbryvdhy32sc-bash42-042 /nix/store/mgsmwwgyi9mjdnihxcyy870ssc38l9c7-bash42-043 /nix/store/376kgxdbmz5r8x3fbiqnkxkqg65a1z4y-bash42-044 /nix/store/j6zng95gbqcxg8xhijm6gb7vrp036hq4-bash42-045 /nix/store/5gh1lr4r2zjacv8m80mwyybax6cj7sk8-bash42-046 /nix/store/rnm9p04557yi06i7ffwiwvimdfa13gis-bash42-047")
  , ("postInstall", "# Add an `sh' -> `bash' symlink.\nln -s bash \"$out/bin/sh\"\n")
  , ("propagatedBuildInputs", "")
  , ("propagatedNativeBuildInputs", "")
  , ("src", "/nix/store/gqadwislqjf5vvrjvgpv247jsyqr7im0-bash-4.2.tar.gz")
  , ("stdenv", "/nix/store/8fbhbn8srgjfxqy83aahiwr5gax2byqb-stdenv-linux-boot")
  , ("system", "x86_64-linux")
  ]
)