This primarily improves support for external signing, as it includes multiple bugfixes for Boost Process. As well as various improvements to the multi-index library.
#23340 rebased.
Guix build:
0bash-5.1# find guix-build-$(git rev-parse --short=12 HEAD)/output/ -type f -print0 | env LC_ALL=C sort -z | xargs -r0 sha256sum
1b5186404303e2a6573a6df404f943f6d172d4965bd9a78d7f9d1f7cf7080b774 guix-build-4bba7ab2ffc3/output/aarch64-linux-gnu/SHA256SUMS.part
29d03756665fac8cb1e3af6623b8cede3032bad6cbc15739db5145c4813f0c2f9 guix-build-4bba7ab2ffc3/output/aarch64-linux-gnu/bitcoin-4bba7ab2ffc3-aarch64-linux-gnu-debug.tar.gz
332897b5fda018d4fe57f65234da9620202de0b774ae4fa454309460ee451ef98 guix-build-4bba7ab2ffc3/output/aarch64-linux-gnu/bitcoin-4bba7ab2ffc3-aarch64-linux-gnu.tar.gz
4f64304b16fbfaf7a7330842bf8f535acacdcdd36ddf185f5dfcdbe184f05571f guix-build-4bba7ab2ffc3/output/arm-linux-gnueabihf/SHA256SUMS.part
5f5cb4c742edf42aec2f64f97c727a8e325050d465ea58ff9c22f8b5b31073879 guix-build-4bba7ab2ffc3/output/arm-linux-gnueabihf/bitcoin-4bba7ab2ffc3-arm-linux-gnueabihf-debug.tar.gz
60f834947a3eb2d802ba4d1d6dbd26fea9d3453bd8c2dedb06fcfbf1498b45433 guix-build-4bba7ab2ffc3/output/arm-linux-gnueabihf/bitcoin-4bba7ab2ffc3-arm-linux-gnueabihf.tar.gz
7389feef0bf716dd7ea7d72d755f999dbd2d3160f895a606ad6f4a14e97083a47 guix-build-4bba7ab2ffc3/output/arm64-apple-darwin/SHA256SUMS.part
8a9c791b6bcc2bbeff0c94f71dbd9967676559297e089079216253e303acd82cb guix-build-4bba7ab2ffc3/output/arm64-apple-darwin/bitcoin-4bba7ab2ffc3-arm64-apple-darwin.tar.gz
955cdef30941f3fc4716bae5be1230b529b171c5e2cd0c18cc57a15206d742a13 guix-build-4bba7ab2ffc3/output/arm64-apple-darwin/bitcoin-4bba7ab2ffc3-osx-unsigned.dmg
105343499bd15ae59627d3b33259ac7ccec8c841c8bc27cd1a47b41389fae48ac3 guix-build-4bba7ab2ffc3/output/arm64-apple-darwin/bitcoin-4bba7ab2ffc3-osx-unsigned.tar.gz
11fbb99e7f3d5249b92c90ba312ac769adfc9813fb70468decd09f722826f48119 guix-build-4bba7ab2ffc3/output/dist-archive/bitcoin-4bba7ab2ffc3.tar.gz
12c5f466eb462dccea8daa10307ff140844f38097b198282600528acd486915e97 guix-build-4bba7ab2ffc3/output/powerpc64-linux-gnu/SHA256SUMS.part
13174c75cbf16f3ca593d1c684b597eb8dac483dc10ae3cd46cbff61d3f70e70a5 guix-build-4bba7ab2ffc3/output/powerpc64-linux-gnu/bitcoin-4bba7ab2ffc3-powerpc64-linux-gnu-debug.tar.gz
141e6692f4876ba13847cd3722c6e2cd3ee886ebede6b12dffa01b1dbc55186358 guix-build-4bba7ab2ffc3/output/powerpc64-linux-gnu/bitcoin-4bba7ab2ffc3-powerpc64-linux-gnu.tar.gz
15dac7f60b99dfb96daf8c3c9a0b98d4ecc3a7ecf7ad6a8dfb879cb61aa4f2e429 guix-build-4bba7ab2ffc3/output/powerpc64le-linux-gnu/SHA256SUMS.part
164cef32efcd9fa591a53ea5354d63e9d6c0d663ae7748599b34427f17ef462f1c guix-build-4bba7ab2ffc3/output/powerpc64le-linux-gnu/bitcoin-4bba7ab2ffc3-powerpc64le-linux-gnu-debug.tar.gz
17d5ac47db91eb0232075a1138cc0ae212516e4f7fa022b2de181533d411a0d507 guix-build-4bba7ab2ffc3/output/powerpc64le-linux-gnu/bitcoin-4bba7ab2ffc3-powerpc64le-linux-gnu.tar.gz
187eb67ea46c7ade1f51928648e664bc2295a96ae0e3f144cf6903f277334b228f guix-build-4bba7ab2ffc3/output/riscv64-linux-gnu/SHA256SUMS.part
19b97d248731573ef3911f4d2750409615a940f975d9c4de783c76beb897a4dd53 guix-build-4bba7ab2ffc3/output/riscv64-linux-gnu/bitcoin-4bba7ab2ffc3-riscv64-linux-gnu-debug.tar.gz
207d2b0cef4cc83dbf54cd1af18fe4cb7b7ea408747e30993c20e1012b1b628373 guix-build-4bba7ab2ffc3/output/riscv64-linux-gnu/bitcoin-4bba7ab2ffc3-riscv64-linux-gnu.tar.gz
21a45eb59edc5a1e8742dd9fce1a9916b43ab2894ff8f3c62d5110a9afa35cf9e9 guix-build-4bba7ab2ffc3/output/x86_64-apple-darwin/SHA256SUMS.part
22504efd5c1131407a3e3120e77a1abe1e183727d995e7cb944c9c8089518314a0 guix-build-4bba7ab2ffc3/output/x86_64-apple-darwin/bitcoin-4bba7ab2ffc3-osx-unsigned.dmg
230f14f26d2074de96d078ea31ef249a6f9ba2db1fec86856496fca5ab2f517cb7 guix-build-4bba7ab2ffc3/output/x86_64-apple-darwin/bitcoin-4bba7ab2ffc3-osx-unsigned.tar.gz
24574aab5513038a80c6cac16eb927d7dcec27b880ffd313c6b56272ed577e2df3 guix-build-4bba7ab2ffc3/output/x86_64-apple-darwin/bitcoin-4bba7ab2ffc3-osx64.tar.gz
25ec7861c9840c2888022a81d5fbb807284c07f603053ba9cc200c103e26379e7f guix-build-4bba7ab2ffc3/output/x86_64-linux-gnu/SHA256SUMS.part
269d1d2fb313d15048ae6b10b9c50942a00ef8c65c367b25656810b3819fdc95ff guix-build-4bba7ab2ffc3/output/x86_64-linux-gnu/bitcoin-4bba7ab2ffc3-x86_64-linux-gnu-debug.tar.gz
27d668065e2de147d352914f0d2f5769051f0ec0a29ce208979758724fe556cc04 guix-build-4bba7ab2ffc3/output/x86_64-linux-gnu/bitcoin-4bba7ab2ffc3-x86_64-linux-gnu.tar.gz
28aa1f2ce87f707d28c137775830da128bd2b49b20eb258ff46a78f1ada1516480 guix-build-4bba7ab2ffc3/output/x86_64-w64-mingw32/SHA256SUMS.part
29bcf3f19575662dadf3f77ca0bd5d4a3268314fd97c46f88679af1977d83863c5 guix-build-4bba7ab2ffc3/output/x86_64-w64-mingw32/bitcoin-4bba7ab2ffc3-win-unsigned.tar.gz
30c8d64700e03757a5f46ec04dc7e2cdf9435ebdee9e6cea5789475ca86461f912 guix-build-4bba7ab2ffc3/output/x86_64-w64-mingw32/bitcoin-4bba7ab2ffc3-win64-debug.zip
3192bd0cb7a43551e89910e8fabfb2915da03835ac074331436e1f159760ed8d19 guix-build-4bba7ab2ffc3/output/x86_64-w64-mingw32/bitcoin-4bba7ab2ffc3-win64-setup-unsigned.exe
32e414c9a500ebf49ef1f2625c6763b945a13d5f1d1c56463f642f325e054f87ed guix-build-4bba7ab2ffc3/output/x86_64-w64-mingw32/bitcoin-4bba7ab2ffc3-win64.zip