doc: clarify that the "-j N" goes after the "--build build" part #32846

pull bigspider wants to merge 1 commits into bitcoin:master from bigspider:patch-1 changing 8 files +20 −20

bigspider commented at 7:22 AM on July 1, 2025: contributor

I was surprised that something like cmake -j 4 --build build doesn't work, so this might help others to not make the same mistake.
DrahtBot added the label Docs on Jul 1, 2025
DrahtBot commented at 7:23 AM on July 1, 2025: contributor


The following sections might be updated with supplementary metadata relevant to reviewers and maintainers.



Code Coverage & Benchmarks

For details see: https://corecheck.dev/bitcoin/bitcoin/pulls/32846.



Reviews

See the guideline for information on the review process.

Type Reviewers

ACK hebasto, stickies-v, pablomartin4btc, theStack, brunoerg, w0xlt, achow101

Stale ACK maflcko

If your review is incorrectly listed, please react with 👎 to this comment and the bot will ignore it on the next update.



Conflicts

Reviewers, this pull request conflicts with the following ones:
- #32269 (doc: update unix build doc with build flags by bufo24)
If you consider this pull request important, please also help to review the conflicting pull requests. Ideally, start with the one that should be merged first.
maflcko commented at 7:30 AM on July 1, 2025: member

lgtm ACK 69f3b2039147558f5c9b452016ab980930e85222
hebasto commented at 8:55 AM on July 1, 2025: member

Concept ACK. It follows CMake docs.

Why not apply such a change across all the docs?

See the output of git grep -i 'Use "-j N"' for relevant instances.
stickies-v commented at 9:06 AM on July 1, 2025: contributor

Concept ACK

See the output of git grep -i 'Use "-j N"' for relevant instances.

Agreed with this. I also couldn't find any other patterns that should be updated here.

Type	Reviewers
ACK	hebasto, stickies-v, pablomartin4btc, theStack, brunoerg, w0xlt, achow101
Stale ACK	maflcko

doc: clarify that the "-j N" goes after the "--build build" part

Also, capitalized the comments in build-unix.md for uniformity
with the docs on other targets.

0e9f409db3

bigspider force-pushed on Jul 1, 2025
bigspider commented at 10:04 AM on July 1, 2025: contributor

Done, and rebased.

I also noticed that the analogous comments were capitalized in all other build-*.md files, so I capitalized them in build-unix.md as well.
hebasto approved
hebasto commented at 10:17 AM on July 1, 2025: member

ACK 0e9f409db3b7b08aef75ce39765b018b69cc8e9d.
DrahtBot requested review from maflcko on Jul 1, 2025
DrahtBot requested review from stickies-v on Jul 1, 2025
in doc/build-windows.md:50 in 0e9f409db3
```
  46 | @@ -47,9 +47,9 @@ This means you cannot use a directory that is located directly on the host Windo
  47 |  
  48 |  Build using:
  49 |  
  50 | -    gmake -C depends HOST=x86_64-w64-mingw32  # Use "-j N" for N parallel jobs.
  51 | +    gmake -C depends HOST=x86_64-w64-mingw32  # Append "-j N" for N parallel jobs.
```
stickies-v commented at 10:43 AM on July 1, 2025:

review note: gmake seems fine with placing -j earlier, so technically this change isn't necessary, but it's probably better to be consistent anyway.

bigspider commented at 10:48 AM on July 1, 2025:

Good point. Same for ctest, I think.

stickies-v commented at 11:04 AM on July 1, 2025:

Oh you're right!
stickies-v approved
stickies-v commented at 10:44 AM on July 1, 2025: contributor

ACK 0e9f409db3b7b08aef75ce39765b018b69cc8e9d

in doc/build-unix.md:13 in 0e9f409db3

   8 | @@ -9,8 +9,8 @@ To Build
   9 |  
  10 |  ```bash
  11 |  cmake -B build
  12 | -cmake --build build    # use "-j N" for N parallel jobs
  13 | -cmake --install build  # optional
  14 | +cmake --build build    # Append "-j N" for N parallel jobs
  15 | +cmake --install build  # Optional

purpleKarrot commented at 11:12 AM on July 1, 2025:

cmake --install supports -j too!

purpleKarrot commented at 11:23 AM on July 1, 2025: contributor

This may be unrelated, but cmake also respects some environment variables. So instead of passing -j to each command, you could just set CMAKE_BUILD_PARALLEL_LEVEL in bashrc or whatever your favorite shell uses. In fish, I use the following:

function cmake
  set -x CMAKE_C_COMPILER_LAUNCHER (which ccache)
  set -x CMAKE_CXX_COMPILER_LAUNCHER (which ccache)
  set -x CMAKE_BUILD_PARALLEL_LEVEL (nproc)
  set -x CMAKE_COLOR_DIAGNOSTICS 1
  set -x CMAKE_EXPORT_COMPILE_COMMANDS 1
  set -x CMAKE_GENERATOR Ninja
  set -x CMAKE_INSTALL_PREFIX $HOME/.local
  set -x CMAKE_POLICY_VERSION_MINIMUM 3.5
  command cmake $argv
end

pablomartin4btc commented at 3:40 PM on July 1, 2025: member

ACK 0e9f409db3b7b08aef75ce39765b018b69cc8e9d
theStack approved
theStack commented at 4:29 PM on July 1, 2025: contributor

ACK 0e9f409db3b7b08aef75ce39765b018b69cc8e9d

Makes sense to clarify, have tripped over this as well in the past.
brunoerg approved
brunoerg commented at 5:11 PM on July 1, 2025: contributor

ACK 0e9f409db3b7b08aef75ce39765b018b69cc8e9d
w0xlt commented at 5:18 PM on July 1, 2025: contributor

ACK https://github.com/bitcoin/bitcoin/pull/32846/commits/0e9f409db3b7b08aef75ce39765b018b69cc8e9d
achow101 commented at 6:56 PM on July 1, 2025: member

ACK 0e9f409db3b7b08aef75ce39765b018b69cc8e9d
achow101 merged this on Jul 1, 2025
achow101 closed this on Jul 1, 2025
bigspider deleted the branch on Jul 1, 2025
fanquake referenced this in commit 83ee49b1dc on Jul 3, 2025
fanquake commented at 4:44 PM on July 3, 2025: member

Backported to 29.x in #32863.