Git fetch method not working right

Git fetch method not working right

[Manolis Ragkousis]

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While I pass to it a specific commit, it downloads a different
(older?) version. I have prepared a testcase with the libpthread,
which is the one that this happens. It will download the files and
then the building will fail, so just compare the file
sysdeps/mach/hurd/pt-sysdep.h with the same file from the commit
e2ae1c43d168fc6f8b34332cbb0656e5d107cbf3 in master. They are
different.

Build it with "./pre-inst-env guix build libpthread -K"

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From e67dcb197cdff59450aa05de6dcdc3f63e22f46e Mon Sep 17 00:00:00 2001
From: Manolis Ragkousis <manolis837@gmail.com>
Date: Tue, 8 Apr 2014 01:41:32 +0000
Subject: [PATCH] Testcase

---
 gnu/packages/hurd.scm | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/gnu/packages/hurd.scm b/gnu/packages/hurd.scm
index f1e7dbc..b23ace3 100644
--- a/gnu/packages/hurd.scm
+++ b/gnu/packages/hurd.scm
@@ -128,4 +128,37 @@ communication.")
      "This package provides C headers of the GNU Hurd, used to build the GNU C
 Library and other user programs.")
     (license gpl2+)))
+
+;;This should download the HEAD of the master branch but it's not
+;;Compare the file sysdeps/mach/hurd/pt-sysdep.h with the same file from 
+;;the commit e2ae1c43d168fc6f8b34332cbb0656e5d107cbf3 in master. They are different
+
+(define-public libpthread 
+  (package
+    (name "libpthread")
+    (version "0.3")
+    (source (origin
+              (method git-fetch)
+              (uri (git-reference
+                    (url "git://git.sv.gnu.org/hurd/libpthread")
+                    (commit "e2ae1c43d168fc6f8b34332cbb0656e5d107cbf3")))
+              (sha256
+               (base32 
+                "0bb8m0pk7b53sww4ahjds77bvqy0alz54g3aylzwncfca52gacqp"))
+              (file-name "libpthread" )))
+    (build-system gnu-build-system)
+    (arguments
+     '(
+       #:phases
+       (alist-replace
+        'unpack
+        (lambda* (#:key inputs source #:allow-other-keys)                                        
+          (mkdir "source")
+          (chdir "source")
+          (copy-recursively source ".")
+           #t)
+        %standard-phases)))
+    (home-page "Testing")
+    (synopsis "Testing")
+    (description "Testing")
+    (license gpl2+)))
-- 
1.9.0

Re: Git fetch method not working right

[Ludovic Courtès]

Manolis Ragkousis <manolis837@gmail.com> skribis:

> While I pass to it a specific commit, it downloads a different
> (older?) version. I have prepared a testcase with the libpthread,
> which is the one that this happens. It will download the files and
> then the building will fail, so just compare the file
> sysdeps/mach/hurd/pt-sysdep.h with the same file from the commit
> e2ae1c43d168fc6f8b34332cbb0656e5d107cbf3 in master. They are
> different.
>
> Build it with "./pre-inst-env guix build libpthread -K"

The build log I have for ‘guix build -S libpthread’ is:

--8<---------------cut here---------------start------------->8---
Cloning into '/gnu/store/hq89ni9pgbsh989kybdv2fgllsyl8aqs-libpthread'...
Checking connectivity... done
Note: checking out 'e2ae1c43d168fc6f8b34332cbb0656e5d107cbf3'.

You are in 'detached HEAD' state. You can look around, make experimental
changes and commit them, and you can discard any commits you make in this
state without impacting any branches by performing another checkout.

If you want to create a new branch to retain commits you create, you may
do so (now or later) by using -b with the checkout command again. Example:

  git checkout -b new_branch_name

HEAD is now at e2ae1c4... Merge branch 'foo'
output path `/gnu/store/hq89ni9pgbsh989kybdv2fgllsyl8aqs-libpthread' should have r:sha256 hash `0bb8m0pk7b53sww4ahjds77bvqy0alz54g3aylzwncfca52gacqp', instead has `0h4k81bkygswcm8s4nwbq9p3gyy3v11syd70vdi5h0sj0jr93y55'
@ build-failed /gnu/store/152jws5fqk7vy0s9j8shnxcmxz9il8cv-libpthread.drv - 1 output path `/gnu/store/hq89ni9pgbsh989kybdv2fgllsyl8aqs-libpthread' should have r:sha256 hash `0bb8m0pk7b53sww4ahjds77bvqy0alz54g3aylzwncfca52gacqp', instead has `0h4k81bkygswcm8s4nwbq9p3gyy3v11syd70vdi5h0sj0jr93y55'
guix build: error: build failed: build of `/gnu/store/152jws5fqk7vy0s9j8shnxcmxz9il8cv-libpthread.drv' failed
--8<---------------cut here---------------end--------------->8---

As you can see, it does check out commit e2ae1c4.  However, the result
doesn’t have the sha256 hash that appears in the recipe, so it fails
(meaning: it cannot possibly go further and start building libpthread.)

What you should be doing is this:

  1. manually do a git checkout of the exact commit that you want;
  2. run ‘rm -rf .git’ in the checkout;
  3. run ‘guix hash -r .’ in the checkout;
  4. put that hash in the recipe.

From there, ‘guix build -S libpthread’ should succeed, and you’ll be
sure it corresponds to the very commit that you have before your eyes.

Can you try that and report back?

Thanks,
Ludo’.

Re: Git fetch method not working right

[Manolis Ragkousis]

Because I didn't change the sha256 hash after changing the commit
hash, it wasn't downloading the new one, but it was reusing the old
one already present from the previous builds. The moment I changed the
sha256 hash to the correct one, it downloaded the correct one and it
worked. All ok now.

Re: Git fetch method not working right

[Ludovic Courtès]

Manolis Ragkousis <manolis837@gmail.com> skribis:

> Because I didn't change the sha256 hash after changing the commit
> hash, it wasn't downloading the new one, but it was reusing the old
> one already present from the previous builds.

Ah right, that’s because /gnu/store is essentially a cache, so it
considered that it already had the directory with that hash, and thus
didn’t re-download it.

> The moment I changed the sha256 hash to the correct one, it downloaded
> the correct one and it worked. All ok now.

Cool!

Ludo’.