Thanks, Tobias. I am now properly populating the store. I have switched to using 'guix graph --type=derivation' to pull in what seems to be the full set of dependencies. I am seeing a strange issue when importing a package. I can typically duplicate and import a file and it is copied to the original location, for example:
----------------------------------------
$ cp -a /gnu/store/v2zls012iwxyw6058cir7n2b792lsvc9-perl-5.30.2.tar.gz perl-5.30.2.tar.gz
$ guix download perl-5.30.2.tar.gz
/gnu/store/v2zls012iwxyw6058cir7n2b792lsvc9-perl-5.30.2.tar.gz
128nfdxcvxfn5kq55qcfrx2851ys8hv794dcdxbyny8rm7w7vnv6
$ cp -a /gnu/store/17acz7ks1f7xn6yp1a2y4g7vc6bhr8wc-make-3.82.tar.gz make-3.82.tar.gz
$ guix download make-3.82.tar.gz
/gnu/store/17acz7ks1f7xn6yp1a2y4g7vc6bhr8wc-make-3.82.tar.gz
1rs2f9hmvy3q6zkl15jnlmnpgffm0bhw5ax0h5c7q604wqrip69x
----------------------------------------
For the Python-3.5.9 tarball the first version loads in the expected way. The second tarball is restored to a new location:
----------------------------------------
$ cp -a /gnu/store/f99fblkzb6ip268sg096shhs7wzjyp55-Python-3.5.9.tar.xz Python-3.5.9.tar.xz
$ guix download Python-3.5.9.tar.xz
/gnu/store/f99fblkzb6ip268sg096shhs7wzjyp55-Python-3.5.9.tar.xz
0jdh9pvx6m6lfz2liwvvhn7vks7qrysqgwn517fkpxb77b33fjn2
$ cp -a /gnu/store/nj79fxxl5wvnq7jpj2wgbx0591gkjw41-Python-3.5.9.tar.xz Python-3.5.9.tar.xz
$ guix download Python-3.5.9.tar.xz
/gnu/store/9sa83nyjlm5dyhwys4imm1wa40mjaw1x-Python-3.5.9.tar.xz
0rkn451qfz3gbni57la00a5fbgish9jmm5bmhmgmf223vxwya447
----------------------------------------
Since the tarball is not restored to the original location the guix build command still attempts the download and fails the offline build.
Greg Hogan