# git-describe --contains fails on given tree 5 messages from 2010-08-21 to 2010-08-23. Participants: Jan Engelhardt, Jakub Narebski, Thomas Rast. Thread: https://gitlist.dev/t/24820 ## Jan Engelhardt, 2010-08-21 19:47 Subject: git-describe --contains fails on given tree Message-ID: URL: https://gitlist.dev/e/alpine.LSU.2.01.1008212145520.14934%40obet.zrqbmnf.qr ``` Hi, for some reason, git-describe cannot figure out v1.17~15^2^2 in the pam_mount tree, despite me being able to actually give a description that would fit the contains syntax: $ git clone git://pam-mount.git.sf.net/gitroot/pam-mount/pam-mount Initialized empty Git repository in /dev/shm/pam-mount/.git/ remote: Counting objects: 7261, done. remote: Compressing objects: 100% (1819/1819), done. remote: Total 7261 (delta 5557), reused 6990 (delta 5348) Receiving objects: 100% (7261/7261), 1.40 MiB | 832 KiB/s, done. Resolving deltas: 100% (5557/5557), done. $ cd pam-mount/ $ git describe --contains v1.17~15^2^2 fatal: cannot describe '95ce932690dfce8cbe50b6a3a8949e41a54c8966' (Expected to get back: v1.17~15^2^2) Why would it not want to return something? Possible bug? Using git 1.7.1 on openSUSE 11.3. thanks, Jan ``` ## Jakub Narebski, 2010-08-21 19:55 Subject: Re: git-describe --contains fails on given tree Message-ID: URL: https://gitlist.dev/e/m3occvoi5c.fsf%40localhost.localdomain In-Reply-To: ``` Jan Engelhardt writes: > Hi, > > > > for some reason, git-describe cannot figure out v1.17~15^2^2 in > the pam_mount tree, despite me being able to actually give > a description that would fit the contains syntax: > > $ git clone > git://pam-mount.git.sf.net/gitroot/pam-mount/pam-mount > Initialized empty Git repository in /dev/shm/pam-mount/.git/ > remote: Counting objects: 7261, done. > remote: Compressing objects: 100% (1819/1819), done. > remote: Total 7261 (delta 5557), reused 6990 (delta 5348) > Receiving objects: 100% (7261/7261), 1.40 MiB | 832 KiB/s, done. > Resolving deltas: 100% (5557/5557), done. > > $ cd pam-mount/ > $ git describe --contains v1.17~15^2^2 > fatal: cannot describe '95ce932690dfce8cbe50b6a3a8949e41a54c8966' > > (Expected to get back: v1.17~15^2^2) > > Why would it not want to return something? Possible bug? Is v1.17 an *annotated* tag? What does $ git describe --contains --tags v1.17~15^2^2 return? -- Jakub Narebski Poland ShadeHawk on #git ``` ## Jan Engelhardt, 2010-08-21 20:42 Subject: Re: git-describe --contains fails on given tree Message-ID: URL: https://gitlist.dev/e/alpine.LSU.2.01.1008212241410.23864%40obet.zrqbmnf.qr In-Reply-To: ``` On Saturday 2010-08-21 21:55, Jakub Narebski wrote: >> for some reason, git-describe cannot figure out v1.17~15^2^2 in >> the pam_mount tree, despite me being able to actually give >> a description that would fit the contains syntax: >> >> $ git clone >> git://pam-mount.git.sf.net/gitroot/pam-mount/pam-mount >> Initialized empty Git repository in /dev/shm/pam-mount/.git/ >> remote: Counting objects: 7261, done. >> remote: Compressing objects: 100% (1819/1819), done. >> remote: Total 7261 (delta 5557), reused 6990 (delta 5348) >> Receiving objects: 100% (7261/7261), 1.40 MiB | 832 KiB/s, done. >> Resolving deltas: 100% (5557/5557), done. >> >> $ cd pam-mount/ >> $ git describe --contains v1.17~15^2^2 >> fatal: cannot describe '95ce932690dfce8cbe50b6a3a8949e41a54c8966' >> >> (Expected to get back: v1.17~15^2^2) >> >> Why would it not want to return something? Possible bug? > >Is v1.17 an *annotated* tag? It certainly is (if it were not, there be no tag, just commit): $ git show v1.17 tag v1.17 Tagger: Jan Engelhardt Date: Mon Jan 26 00:41:17 2009 +0100 pam_mount 1.17 -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (GNU/Linux) iEYEABECAAYFAkl8+J8ACgkQ92gFgoRMQ2Dd7QCeJj/u543aBiK/Los8LgvdkR/1 6nwAnA/CB23vjxFpVWsKZIW99GHxDglX =yLqV -----END PGP SIGNATURE----- >What does > > $ git describe --contains --tags v1.17~15^2^2 "Cannot describe 95ce..." Funny thing is, describing "v1.17~15^2" does work, as does "v1.17~15^1". ``` ## Thomas Rast, 2010-08-22 21:58 Subject: Re: git-describe --contains fails on given tree Message-ID: <201008222358.04504.trast@student.ethz.ch> URL: https://gitlist.dev/e/201008222358.04504.trast%40student.ethz.ch In-Reply-To: ``` Jan Engelhardt wrote: > > On Saturday 2010-08-21 21:55, Jakub Narebski wrote: > >> for some reason, git-describe cannot figure out v1.17~15^2^2 in > >> the pam_mount tree, despite me being able to actually give > >> a description that would fit the contains syntax: > >What does > > > > $ git describe --contains --tags v1.17~15^2^2 > > "Cannot describe 95ce..." > > Funny thing is, describing "v1.17~15^2" does work, as does "v1.17~15^1". That's clock skew: $ git show -s --format="%cd" v1.17~15^2 Fri Jan 9 04:35:59 2009 +0100 $ git show -s --format="%cd" v1.17~15^2^2 Sat Jan 24 16:35:34 2009 +0100 Note how the parent commit is far newer than the child. git-name-rev (which is what really drives git describe --contains) concludes that it can stop searching along this line of history. Interestingly, --stdin disables this optimization: $ git rev-parse v1.17~15^2^2 | git name-rev --stdin 95ce932690dfce8cbe50b6a3a8949e41a54c8966 (tags/v1.17~15^2^2) -- Thomas Rast trast@{inf,student}.ethz.ch ``` ## Jan Engelhardt, 2010-08-23 11:26 Subject: Re: git-describe --contains fails on given tree Message-ID: URL: https://gitlist.dev/e/alpine.LNX.2.01.1008231324280.17348%40obet.zrqbmnf.qr In-Reply-To: <201008222358.04504.trast@student.ethz.ch> ``` On Sunday 2010-08-22 23:58, Thomas Rast wrote: >> On Saturday 2010-08-21 21:55, Jakub Narebski wrote: >> >> for some reason, git-describe cannot figure out v1.17~15^2^2 in >> >> the pam_mount tree, despite me being able to actually give >> >> a description that would fit the contains syntax: >> >What does >> > >> > $ git describe --contains --tags v1.17~15^2^2 >> >> "Cannot describe 95ce..." >> >> Funny thing is, describing "v1.17~15^2" does work, as does "v1.17~15^1". > >That's clock skew: > > $ git show -s --format="%cd" v1.17~15^2 > Fri Jan 9 04:35:59 2009 +0100 > > $ git show -s --format="%cd" v1.17~15^2^2 > Sat Jan 24 16:35:34 2009 +0100 Thanks for pointing that out. (Ah the joy of BSD-inside-VMware.) >Interestingly, --stdin disables this optimization: > > $ git rev-parse v1.17~15^2^2 | git name-rev --stdin > 95ce932690dfce8cbe50b6a3a8949e41a54c8966 (tags/v1.17~15^2^2) ```