# Upgrade Pgsql > Build libpq for hMailServer and/or bump the pinned PostgreSQL version, for 15.x and 16.x (e.g. rebuild 15.18 against a new OpenSSL, or upgrade 15.18 -> 15.19). Builds libpq into %hMailServerLibs% via libraries\build-pgsql.ps1 (linking it against the OpenSSL hMailServer uses), rewrites every pinned PostgreSQL version reference in the repo, keeps the README build instructions current, and verifies hMailServer still compiles and links. Use when asked to build, rebuild, bump, update, or upgrade PostgreSQL/libpq for hMailServer. Supports PostgreSQL 15.x/16.x only. - Skill: `hmailserver/upgrade-pgsql` (Agent Skill) - Install (CLI): `npx skillmds@latest add hmailserver/upgrade-pgsql` - Raw SKILL.md: https://api.skillmd.com/api/skills/hmailserver/upgrade-pgsql/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Coding & Dev Tools - Author: hmailserver (https://skillmd.com/u/hmailserver) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/hmailserver/upgrade-pgsql --- # Build / upgrade libpq (PostgreSQL 15.x/16.x) for hMailServer hMailServer talks to PostgreSQL through libpq. PostgreSQL is not vendored in the repo; libpq is built locally into `%hMailServerLibs%\postgresql-\Release\libpq`, and its concrete version is pinned in a few build/config files. This skill builds libpq (linking it against the OpenSSL hMailServer uses), rewrites those references when the version changes, and verifies the build. There are two reasons to run it: - **Rebuild libpq** at the *current* pinned version — most often to relink it against a freshly built OpenSSL (see the OpenSSL skill's libpq note). No version rewrites needed. - **Bump the PostgreSQL version** (e.g. `15.18 -> 15.19`) — build the new version *and* rewrite the pinned references. ## Scope - **PostgreSQL 15.x and 16.x only.** These ship the `src\tools\msvc\build.pl` MSVC build system this skill drives. **PostgreSQL 17 removed it** in favour of Meson; if the requested target is 17.x or newer, stop and tell the user it is out of scope — the build recipe differs and this skill is not validated for it. Reject anything not matching `^1[56]\.\d+$`. - libpq links against OpenSSL at build time. The build script points `config.pl`'s `openssl` entry at `%hMailServerLibs%\openssl-\out64`, so **a matching OpenSSL build must already exist** (build it first with the upgrade-openssl skill / `build-openssl.ps1`). - Updating any CI/CD-built copy of libpq is out of scope, but the README build instructions must stay accurate. ## Steps ### 1. Determine current and target version - Read the current PostgreSQL version by searching `hmailserver/source/Server/hMailServer/post-build.bat` for `postgresql-1[56]\.\d+` (e.g. `postgresql-15.18`). - Take the target version from the user (e.g. `15.19`). For a pure rebuild, the target equals the current version. - **Validate the target matches `^1[56]\.\d+$`.** Abort with the out-of-scope message above if it does not. - Read the OpenSSL version libpq should link against from `hmailserver/source/Server/hMailServer/hMailServer.vcxproj` (`openssl-`). The build script auto-detects this same value, so you normally do not need to pass it. ### 2. Build libpq Invoke the build script (prerequisites — `%hMailServerLibs%`, an existing `openssl-\out64`, Perl on PATH, VS2019/VS2022 x64 tools — are validated inside it; surface its error message if it fails): ``` powershell.exe -NoProfile -ExecutionPolicy Bypass -File libraries\build-pgsql.ps1 -Version ``` Pass `-OpenSSLVersion ` only to override the auto-detected value. **Run this through the native PowerShell tool, NOT the Bash tool.** The Bash tool prepends MSYS/Git (`/usr/bin`) to `PATH`, which shadows Strawberry Perl with an MSYS Perl that is missing modules PostgreSQL's `build.pl` needs, and puts a GNU `tar` ahead of the Windows `bsdtar` (GNU tar misreads the `C:` in `C:\...` as a remote rmt host — "Cannot connect to C: resolve failed"). The native PowerShell tool has a clean Windows `PATH` where `perl` resolves to Strawberry Perl. The script also pins tar to `%SystemRoot%\System32\tar.exe` defensively, but Perl must still come from the Windows PATH. The build takes several minutes and the PowerShell tool only returns its captured output once it finishes, so the console can look stalled. The script mirrors every step to `libraries\build-pgsql.log` (git-ignored via `*.log`) as it runs. Tell the user they can watch progress live from another shell with `Get-Content libraries\build-pgsql.log -Wait`, and if the script fails, read that log for the full transcript rather than relying on the (often truncated) captured console output. On success it produces `%hMailServerLibs%\postgresql-\Release\libpq` containing `libpq.dll` and `libpq.lib`, and the `libpq-fe.h` header under `src\interfaces\libpq`. Only proceed if the script exits 0. ### 3. Rewrite the pinned version references **Skip this step for a pure rebuild** (target == current). Otherwise replace the old version with the new one (`postgresql-` -> `postgresql-`) in these files: | File | Occurrences | |------|-------------| | `hmailserver/source/Server/hMailServer/post-build.bat` | 1 (the `xcopy` of libpq DLLs) | | `hmailserver/source/Server/hMailServer/hMailServer.vcxproj` | 6 (include-dir + `src\include` + lib-dir, across Debug and Release) | | `hmailserver/installation/hMailServer64.iss` | 1 (`POSTGRESQL_LIBPQ_PATH`) | | `README.md` | 3 (the download / cd instructions in "Building PostgreSQL") | | `.claude/skills/upgrade-openssl/SKILL.md` | 1 (the libpq-note path, to keep cross-references consistent) | Then grep the whole repo for `postgresql-\d` and confirm the only remaining matches are the intentional ones you just rewrote — there must be **zero** references to the old concrete version. **Do not** change the `libpq.dll` / `libpq.lib` names (in `section_files_64.iss` and the `hMailServer.vcxproj` linker deps) or the `` include in `Common/SQL/PGRecordset.h` / `PGConnection.h`. Those are not version-bearing. ### 4. Keep build instructions current The `README.md` "Building PostgreSQL" section documents the manual recipe the script automates. On a version bump, update its version numbers (step 3 already covers the `postgresql-` strings). Skim the new release's notes; only if PostgreSQL changed the build process (e.g. dropped/changed `src\tools\msvc\build.pl`, new flags) update both `libraries\build-pgsql.ps1` and the README accordingly. State whether a change was needed. ### 5. Verify Build hMailServer to confirm it compiles and links against the new libpq: ``` powershell.exe -NoProfile -ExecutionPolicy Bypass -File build\build.ps1 ``` The link step pulls `libpq.lib` from the new `postgresql-\Release\libpq`, so a successful link confirms the reference updates are consistent. `post-build.bat` copies the new `libpq.dll` into the output dir. Confirm `libpq.dll` links against the expected OpenSSL DLLs (`libssl-3-x64.dll` / `libcrypto-3-x64.dll`) by dumping its import table with `dumpbin /dependents` (the CLI equivalent of the README's [Dependencies](https://github.com/lucasg/Dependencies/releases) tool TIP — no extra tooling needed since `dumpbin` ships with VS): ``` powershell.exe -NoProfile -Command "$d = Get-ChildItem 'C:\Program Files*\Microsoft Visual Studio\*\*\VC\Tools\MSVC\*\bin\Hostx64\x64\dumpbin.exe' | Select-Object -First 1; & $d.FullName /dependents \"$env:hMailServerLibs\postgresql-\Release\libpq\libpq.dll\"" ``` Under `Image has the following dependencies:` both `libssl-3-x64.dll` and `libcrypto-3-x64.dll` must be listed (dynamic-linked OpenSSL, in lockstep with the rest of hMailServer). If instead you see no OpenSSL DLLs, libpq was built without SSL (missing/mismatched `openssl-\out64` at build time) — rebuild it (step 2) before shipping. The other entries (`Secur32`, `WS2_32`, `KERNEL32`, `VCRUNTIME140`, the `api-ms-win-crt-*` set) are the expected Windows/CRT dependencies and need no action. ## Reference: all PostgreSQL/libpq touch points - **Version-pinned (edited by step 3):** `post-build.bat`, `hMailServer.vcxproj`, `hMailServer64.iss`, `README.md`, and the libpq note in the upgrade-openssl skill. - **Build recipe (edited only if the release changes it):** `libraries\build-pgsql.ps1`, `README.md`. - **Not version-bearing (leave alone):** `libpq.dll` / `libpq.lib` names in `section_files_64.iss` and the `hMailServer.vcxproj` linker dependencies; the `` includes in `Common/SQL/PGRecordset.h` and `Common/SQL/PGConnection.h`. ## Note The script's own end-to-end run needs the PostgreSQL source download, the VS2019/VS2022 x64 toolchain, Perl, and a matching `openssl-\out64` build present; it validates those prerequisites and fails early with a clear message if any is missing.