On Friday 16 of January 2015 16:43:20 Dimitrios Apostolou wrote: > (Cross posting to both bug-automake and bug-tar as I can see both projects > being affected.) > (Please keep me CC'd as I'm not subscribed.) > > Hello, > > this bug report is because of the following messages when extracting a > source tarball generated with "make dist". You can read the full bug > report at https://dev.cfengine.com/issues/6925. > > # tar -xzf core/cfengine-3.7.0a1.5ffcc54.tar.gz > tar: > cfengine-3.7.0a1.5ffcc54/tests/acceptance/17_users/unsafe/10_modify_user_with_same_password.cf: > Cannot hard link to > `cfengine-3.7.0a1.5ffcc54/tests/acceptance/17_users/unsafe/20_modify_user_with_same_password_hpux_tru': > No such file or directory > [...] > > Regading automake, it implements "make dist" using "tar -chf" where -h > stands for --dereference, i.e. it dereferences all symlinks. I believe > I've read that it is for portability, because symlinks are handled in a > variety of manners in different tar implementations. However as seen > above, what actually happens is that GNU tar stores the symlinks as > hardlinks. Because the total path length of the hardlinks is more than 100 > characters, they get truncated due to "ustar" format limitations (ustar > format is chosen using the "tar-ustar" automake option).
When using automake, try to use: AM_INIT_AUTOMAKE([filename-length-max=99]) That breaks 'make dist' as you would expect. Maybe this could be done by default for certain archive formats (or make dist could be silenced a little to see tar's warnings). > Please notice that removing "-h" fixes the problem. Symlinks are stored > properly as their length is much smaller than 100 chars (because they are > relative symlinks). Not much - when 'tar chf -' (and in your example) the symlinks are probably just (with a bit of luck) a bit smaller than not archived files. > Another workaround (the one I chose to use) is to pass the > --hard-dereference to GNU tar in order to store the content of the files > itself, avoiding all kind of links, and maintaining best portability. So > I've added the following lines in my Makefile.am: Also, when fighting with 'tar chf -', you may AC_SUBST([am__tar]) to whatever you want. This would replace what is automatically detected by m4/tar.m4. Pavel
