4 ms·

you know about rerere right? https://www.git-scm.com/book/en/v2/Git-Tools-Rerere https://www.git-scm.com/book/en/v2/Git-Tools-Rerere

by zemo 6y ago

MattIPv4 6y ago
I feel like this is missing something about the drawbacks? Or are there truly no drawbacks beyond disk usage for the cache, and folks should just enable it once they're aware it exists?
- mekkkkkk 6y ago
  I guess it involves a bit of assumptions and guesswork to automatically replay your previous actions to files that in turn may have changed. It probably slightly increases the chances of Git doing something you didn't expect, and not tell you about it. Hence why it isn't default. Maybe?
avodonosov 6y ago
No, I did hot know that, repeated everything manually. Will try that next time, thank you. BTW, pijul docs mention rerere as helping "in some cases": > This is why in these systems, conflicts are often painful, as there is no real way to solve a conflict once and for all (for example, Git has the rerere command to try and simulate that in some cases). https://pijul.org/manual/why_pijul.html https://pijul.org/manual/why_pijul.html
- bombcar 6y ago
  I feel their example (with the ABGX) just makes me think "merging can result in weirdness silently and git and pijul do it different but silent" - it doesn't really argue that one is better than the other. (Most people probably use git as an effectively infinite string of zip files anyway. https://xkcd.com/1597/ https://xkcd.com/1597/ )
  - pmeunier 6y ago
    To the contrary, that example actually gives a solid argument for three points where Pijul is better than Git: 1. The order between lines is preserved by Pijul. This is important: let's say Alice works at the beginning of the file (lines 1-10 of 1000), whereas Bob works at the end (lines 990-1000 of 1000). Pijul preserves the order in all cases, whereas Git might randomly decide, based on the contents of the lines, to merge Bob's new lines in the middle of Alice's new lines. 2. Git solves an optimisation problem (3-way merge) that may have multiple solutions. Unfortunately, there is no way to count the number of solutions, or even to tell whether there are multiple solutions, in a reasonable amount of time. Git therefore picks one solution silently, based on the contents of the lines. In contrast to that, Pijul is deterministic. 3. Pijul is associative, meaning that merging A and (BC) is the same as first merging A and B, and then merging C; in other words, you can merge a branch commit by commit. Git doesn't have that property: if you merge a branch, you MUST (1) stop working on it, or else the future merges become totally unpredictable, and artificial conflicts might come back (yes, I know about dirty-hacks-to-try-and-fix-that-when-they-work such as rerere), and (2) check the result of the merge extremely carefully, because in addition to the logical errors that merges can reasonably introduce, Git might also introduce extra unpredictable errors by randomly shuffling lines around.
    - bombcar 6y ago
      That makes it more clear - the A B C explanation is too simplistic.

you know about rerere right? https://www.git-scm.com/book/en/v2/Git-Tools-Rerere https://www.git-scm.com/book/en/v2/Git-Tools-Rerere

by zemo 6y ago

you know about rerere right? https://www.git-scm.com/book/en/v2/Git-Tools-Rerere https://www.git-scm.com/book/en/v2/Git-Tools-Rerere

MattIPv4 6y ago

I feel like this is missing something about the drawbacks? Or are there truly no drawbacks beyond disk usage for the cache, and folks should just enable it once they're aware it exists?

mekkkkkk 6y ago
I guess it involves a bit of assumptions and guesswork to automatically replay your previous actions to files that in turn may have changed. It probably slightly increases the chances of Git doing something you didn't expect, and not tell you about it. Hence why it isn't default. Maybe?

avodonosov 6y ago

No, I did hot know that, repeated everything manually. Will try that next time, thank you. BTW, pijul docs mention rerere as helping "in some cases": > This is why in these systems, conflicts are often painful, as there is no real way to solve a conflict once and for all (for example, Git has the rerere command to try and simulate that in some cases). https://pijul.org/manual/why_pijul.html https://pijul.org/manual/why_pijul.html

bombcar 6y ago
I feel their example (with the ABGX) just makes me think "merging can result in weirdness silently and git and pijul do it different but silent" - it doesn't really argue that one is better than the other. (Most people probably use git as an effectively infinite string of zip files anyway. https://xkcd.com/1597/ https://xkcd.com/1597/ )
- pmeunier 6y ago
  To the contrary, that example actually gives a solid argument for three points where Pijul is better than Git: 1. The order between lines is preserved by Pijul. This is important: let's say Alice works at the beginning of the file (lines 1-10 of 1000), whereas Bob works at the end (lines 990-1000 of 1000). Pijul preserves the order in all cases, whereas Git might randomly decide, based on the contents of the lines, to merge Bob's new lines in the middle of Alice's new lines. 2. Git solves an optimisation problem (3-way merge) that may have multiple solutions. Unfortunately, there is no way to count the number of solutions, or even to tell whether there are multiple solutions, in a reasonable amount of time. Git therefore picks one solution silently, based on the contents of the lines. In contrast to that, Pijul is deterministic. 3. Pijul is associative, meaning that merging A and (BC) is the same as first merging A and B, and then merging C; in other words, you can merge a branch commit by commit. Git doesn't have that property: if you merge a branch, you MUST (1) stop working on it, or else the future merges become totally unpredictable, and artificial conflicts might come back (yes, I know about dirty-hacks-to-try-and-fix-that-when-they-work such as rerere), and (2) check the result of the merge extremely carefully, because in addition to the logical errors that merges can reasonably introduce, Git might also introduce extra unpredictable errors by randomly shuffling lines around.
  - bombcar 6y ago
    That makes it more clear - the A B C explanation is too simplistic.