Windows post-create-command does not pass '\' correctly to external command

[rasusmilch]

I'm trying to get rustic to correctly pass the file to par2 using the repository config file on a Windows 10 machine.

In the config file I have:

[repository.options]
post-create-command = 'C:\\Users\\rsusmilch\\scoop\\shims\\par2j.exe.exe c -rn1 -rr10 %file'

However, it looks like rustic is not correctly passing the file to the external program as the output shows:

Parchive 2.0 client version 1.3.3.2 by Yutaka Sawada

Base Directory  : "C:\Users\rsusmilch\"
Recovery File   : "C:\Users\rsusmilch\Usersrsusmilchrustic-backup434dataeded50da651889c1de6d6e62f5ad0447d83bf5475ab79ed3e6fd4658f742a9651c.par2"
CPU thread      : 6 / 12
CPU cache limit : 64 KB, 768 KB
CPU extra       : x64 AVX2 CLMUL
Memory usage    : Auto (1615 MB available), Fast SSD

input file is not found, Usersrsusmilchrustic-backup434dataeded50da651889c1de6d6e62f5ad0447d83bf5475ab79ed3e6fd4658f742a[00:05:00] backing up...                  
[WARN] post-create: command was not successful for filename C:\Users\rsusmilch\rustic-backup\434\data\ed\ed50da651889c1de6d6e62f5ad0447d83bf5475ab79ed3e6fd4658f742a9651c, type data, id ed50da651889c1de6d6e62f5ad0447d83bf5475ab79ed3e6
[00:05:01] backing up...                  

I'm new to rust programming and so the source code doesn't help me find where the %file output is generated so I can't decipher anything sadly. Is there a configuration issue? Bug? Should I just manually crawl the directory structure and handle the files?

Thanks!

[rasusmilch]

Turning on trace logging I see:

11:59:42 [DEBUG] (1) rustic_backend::local: calling C:\\Users\\rsusmilch\\scoop\\shims\\par2j.exe.exe c -rn1 -rr10 C:\Users\rsusmilch\rustic-backup\434\snapshots\d4b201eeb1c6b6abcf66c41e3c57d23f60bf464895d6f022ac351516dd1ac75a...
11:59:42 [WARN] post-create: command was not successful for filename C:\Users\rsusmilch\rustic-backup\434\snapshots\d4b201eeb1c6b6abcf66c41e3c57d23f60bf464895d6f022ac351516dd1ac75a, type snapshots, id d4b201eeb1c6b6abcf66c41e3c57d23f60bf464895d6f022ac351516dd1ac75a: exit code: 1

[aawsome]

@rasusmilch Thanks for asking!
Note that windows is not fully supported and path handling is one of the issues here..

But in your case, I actually wonder why you are having double backslashes \ - actually a single one should suffice, IMO.

It also seems to me that your command is only able to handle paths with a double backslash which also surprises me (or I don't know what's going on with windows here...). Actually the command is called directly with the correct file name, see https://github.com/rustic-rs/rustic_core/blob/main/crates/backend/src/local.rs#L118

Note that you can also use %type and %id to self-construct the filename to use in your script.

[rasusmilch]

I agree that they should work without escaping the slashes. However, in my backup config toml file I need to escape \ and spaces or I get the following error:

[WARN] ignoring error O:Test: IO error for operation on O:Test: The system cannot find the file specified. (os error 2)
[WARN] ignoring error EngWK260: IO error for operation on EngWK260: The system cannot find the file specified. (os error 2)

My config toml has this listed for the backup source:

[[backup.sources]]
source = 'O:\Test Eng\WK260'
label = 'WK260'

It only works if I escape the path like this:

[[backup.sources]]
source = 'O:\\Test\ Eng\\WK260'
label = 'WK260'

Notice that the error shows that O:Test stripped out the \ and stopped at the space in the path. Then it started again after the space and stripped the \ again giving EngWK260.

I suspect a similar thing is happening when the program is outputting the filename, since it seems the passed file according to par2 is:
C:\Users\rsusmilch\Usersrsusmilchrustic-backup434dataeded50da651889c1de6d6e62f5ad0447d83bf5475ab79ed3e6fd4658f742a9651c.par2.

You can see my directory of the repository is stripped of the drive letter C: and \.
For reference my repo is repository = 'C:\Users\rsusmilch\rustic-backup\434' which DOES work with single \ and needs no escaping.

Strange...

[simonsan]

The first \ escapes the second \. You can also try using a forward slash / on windows. Instead of the escaped \, it should work as well.

[aawsome]

Ah, I got it. shellword's split is used to split the the actual command and this handles escaped strings... This is why you need to escape the \ in your command.
Unfortunately it is used after the variables are substituted. And in the variable substitutions only single \ are inserted as the paths are taken literally.

Maybe we should apply the substitutions after splitting with shellwords?

[fbewivpjsbsby]

I can run par2 using this command. But is says "The process cannot access the file because it is being used by another process". I've added rustic.exe and par2.exe to Windows Defender exclusion.

'cmd /c "par2 create -qq -n1 -r5 %file"'

"par2 create -qq -n1 -r5 \"%file\""

Log

[INFO] using config .\rustic.toml
[DEBUG] (1) rustic_backend::local: calling cmd /c "par2 create -qq -n1 -r5 C:\rustic\keys\bd8fbe20e67
7e9ff3ab65bd4a3844eba866d6a5714741a0b087abd192b3813ad"...

Could not open "C:\rustic\keys\bd8fbe20e677e9ff3ab65bd4a3844eba866d6a5714741a0b087abd192b3813ad": The process cannot access the file because it is being used by another process.

[WARN] post-create: command was not successful for filename C:\rustic\keys\bd8fbe20e677e9ff3ab65bd4a3
844eba866d6a5714741a0b087abd192b3813ad, type keys, id bd8fbe20e677e9ff3ab65bd4a3844eba866d6a5714741a0b087abd
192b3813ad: exit code: 6
[INFO] key bd8fbe20 successfully added.
[DEBUG] (1) rustic_backend::local: calling cmd /c "par2 create -qq -n1 -r5 C:\rustic\config"...

Could not open "C:\rustic\config": The process cannot access the file because it is being used by another process.

[WARN] post-create: command was not successful for filename C:\rustic\config, type config, id 1c9ae96
108cb140ae6dd2fba3f20a7407cf474562043b15ff5b8312004961079: exit code: 6
[INFO] repository 71c63964 successfully created.

Config

[global]
log-level = "debug" # any of "off", "error", "warn", "info", "debug", "trace"; default: "info"
dry-run = false

[repository]
repository = "C:\\rustic"
password = "test"

[repository.options]
post-create-command = 'cmd /c "par2 create -qq -n1 -r5 %file"'
# post-create-command = "par2 create -qq -n1 -r5 \"%file\""

post-delete-command = "sh -c \"rm -f %file*.par2\""